.SYNOPSIS...SUBTROPICAL RIDGE WILL REMAIN THE DOMINANT WX FEATUREINTO NEXT WEEK. A TUTT WILL THEN MOVE FROM THE TROP ATLC ACROSSTHE CARIB MID NEXT WEEK.

&&

.DISCUSSION...HURRICANE LESLIE WILL CONTINUE TO DOMINATE THE LOWLEVEL WIND FLOW THROUGH FRI NIGHT. AS LESLIE BEGINS TO ACCELERATETO THE NORTH ON SATURDAY WINDS WILL TURN MORE SOUTHEASTERLY RESULTINGIN HOTTER TEMPERATURES FOR SAT AND SUN. NOTE THAT GFS MEX/MOSGUIDANCE SEEMS TOO COOL WITH HIGHS ONLY AROUND 90. MODELS INDICATEBEST MOISTURE AND CONVECTIVE INSTABILITY THAT WE ARE LIKELY TO SEEOVER THE NEXT SEVEN DAYS TOMORROW AFTERNOON. OVER THE WEEKEND...MODELSSHOW MID LEVEL RIDGE BUILDING/STRENGTHENING OVER THE AREA WITH ASTRONG SUBSIDENCE INVERSION ESTABLISHING. MOISTURE ERODES QUICKLYWITH PWAT DROPPING TO AROUND AN INCH WHICH IS BELOW TWO STANDARDDEVIATIONS BELOW NORMAL. NOT ONLY PRECIP WILL BE HARD TO COME BYBUT ALSO CLOUDS. STRONG CAPPING HOLDS THROUGH MUCH OF NEXT WEEKWITH VERY LITTLE MOISTURE ADVECTION.

&&

.AVIATION...LOW LEVEL WINDS WILL REMAIN FROM THE NORTHWEST THROUGH FRINIGHT ESPECIALLY AT JSJ THEN BECOME MORE SOUTHERLY OR SOUTHEASTERLYSAT AND SUN. THIS WILL CAUSE SIG IMPACTS TO AIRCRAT OPERATIONS ATJSJ.

&&

.MARINE...NORTH SWELLS PROPAGATING FROM LESLIE WILL BEGIN TO REACHTHE ATLC COASTAL WATERS TONIGHT AND PEAK FRI. HOWEVER...THE SWELLSWILL BE SLOW TO SUBSIDE OVER THE WEEKEND. FOR NOW CWF CARRIES SEASUP TO 6 FT HOWEVER THESE MAY NEED TO BE REVISED.

&&

.CLIMATE...THE FIRST HALF OF SEP LOOKS LIKE IT WILL BE THE DRIESTON RECORD FOR MUCH OF PR AS A STRONG RIDGE OF HIGH DOMINATES. VERYLITTLE IF ANY PRECIP IS EXPECTED THROUGH SEP 15TH.

.SYNOPSIS...THE UPPER LOW/TROUGH OVER THE MONA PASSAGE WILLCONTINUE TO LIFT TO THE NORTH TODAY THROUGH TONIGHT. TROPICALSTORM RAFAEL WAS MOVING NORTHWEST EARLY THIS MORNING AND AGRADUAL TURN TO THE NORTH-NORTHWEST IS EXPECTED LATER TODAY. ONTHE FORECAST TRACK...THE CENTER OF RAFAEL WILL BE MOVING VERY NEAROR ACROSS THE U.S. VIRGIN ISLANDS LATE THIS AFTERNOON THROUGHTONIGHT.

&&

.DISCUSSION...LATEST NHC TRACK HAS THE CENTER OF RAFAEL MOVINGVERY NEAR OR ACROSS THE U.S. VIRGIN ISLANDS LATE THIS AFTERNOONTHROUGH TONIGHT. HOWEVER...RAFAEL IS STILL NOT WELL ORGANIZED ANDIS IN ITS FORMATIVE STAGES. THIS MEANS THAT SOME ADDITIONALADJUSTMENTS TO THE TRACK COULD STILL OCCUR DURING THE NEXT 12 TO24 HOURS. SOME SLOW STRENGTHENING IS FORECAST DURING THE NEXTCOUPLE OF DAYS. RAIN BANDS ARE EXPECTED TO INCREASE ACROSS THELOCAL AREA FROM EAST SOUTHEAST TO WEST NORTHWEST TODAY THROUGHTONIGHT...WITH PERIODS OF HEAVY RAINFALL EXPECTED. FOR THE U.S.VIRGIN ISLANDS...THE BULK OF THE RAIN IS EXPECTED MAINLY LATETODAY AND TONIGHT AND OVER PUERTO RICO SUNDAY...AS RAFAEL BEGINSMOVING AWAY FROM THE LOCAL REGION AND WINDS SHIFT TO THESOUTHWEST.

CURRENTLY...THE MAIN IMPACTS ARE EXPECTED TO BE RAINFALL AND THEPOTENTIAL FOR FLOODING...WITH SECONDARY IMPACTS BEING INCREASINGWINDS AND SEAS...RIP CURRENTS AND LOCALLY ROUGH SURF.

ALL LOCAL RESIDENTS AND VISITORS SHOULD CONTINUE TO CLOSELYMONITOR THE PROGRESS OF RAFAEL DURING THE COUPLE OF DAYS.

&&

.AVIATION...MVFR OR EVEN LOCAL IFR CONDITIONS ARE EXPECTED TODAYTHROUGH TONIGHT ACROSS THE U.S. VIRGIN ISLANDS AND THE LEEWARDISLANDS IN INCREASING BANDS OF SHOWERS AND THUNDERSTORMS.ELSEWHERE...PREVAILING VFR CONDITIONS ARE EXPECTED EARLY TODAY...WITH MVFR AND LOCAL IFR CONDITIONS BECOMING MORE PREVALENT LATERTODAY THROUGH TONIGHT IN INCREASING BANDS OF SHOWERS ANDTHUNDERSTORMS.

&&

.MARINE...CONDITIONS WILL DETERIORATE FROM SOUTHEAST TO NORTHWESTTODAY...AS TROPICAL STORM RAFAEL MOVES CLOSER TO THE LOCAL AREA.A TROPICAL STORM WARNING CONTINUES FOR THE LOCAL ATLANTIC OFFSHORE WATERS AND THE WATERS SURROUNDING THE U.S. VIRGIN ISLANDS.A TROPICAL STORM WATCH REMAINS IN EFFECT ELSEWHERE.

&&

.HYDROLOGY...A FLASH FLOOD WATCH REMAINS IN EFFECT FOR ALL OF THEU.S. VIRGIN ISLANDS THROUGH SUNDAY AFTERNOON. THE EARLY RAINFALLESTIMATE FOR THESE AREAS IS GENERALLY 3 TO 5 INCHES...WITHLOCALLY HIGHER AMOUNTS POSSIBLE. AS THIS SYSTEM CONTINUES TOEVOLVE...THESE NUMBERS MAY NEED TO BE ADJUSTED. ALSO...GIVEN THEWESTWARD SHIFT IN THE FORECAST TRACK...SOMEWHAT BETTER COVERAGEOF RAIN BANDS IS EXPECTED ACROSS CULEBRA...VIEQUES AND EASTERNPUERTO RICO...AND AN EARLY ESTIMATE FOR THESE AREAS IS 1 TO 3INCHES...WITH LOCALLY HIGHER AMOUNTS POSSIBLE.

.SYNOPSIS...AT UPPER AND MID LEVELS...A LOW REMAINS EAST NORTHEASTOF THE LOCAL AREA THROUGH MID WEEK NEXT WEEK.

AT LOWER LEVELS...HIGH PRESSURE NORTHEAST OF THE AREA IS FORCEDBACK OVER THE SOUTHEAST UNITED STATES BY A VERY LARGE LOW PRESSUREIN THE CENTRAL NORTHEAST ATLANTIC BY THE END OF THE WEEK. THISLOW AND A WEAK LOW PRESSURE NORTH OF THE AREA WILL WEAKEN THETRADE WINDS...BUT THEY RESUME BY MID WEEK NEXT WEEK WHEN HIGHPRESSURE REGAINS CONTROL OF THE MID ATLANTIC.

&&

.DISCUSSION...RADAR IS PEPPERED WITH SHOWERS ANDTHUNDERSTORMS...SOME OF WHICH HAVE BROKEN THROUGH THE 50 KFTLEVEL. LOW LEVEL FLOW IS NEARLY EAST AND MUCH OF THE EASTERN THIRDOF PUERTO RICO HAS SEEN SOME RAIN...WITH AT LEAST ONE HALF INCHSEEN IN NAGUABO SINCE MIDNIGHT. MAJOR MODELS ARE NOT IN AGREEMENTWITH THE TIMING OR THE INTENSITY OF THE ARRIVAL OF THE DRIER AIRTHAT IS CLEARLY SEEN IN THE MIMIC PRODUCT NOSING IN FROM THEEAST NORTHEAST OUT OF THE CENTRAL ATLANTIC. THIS SHOULD BRINGSLIGHTLY COOLER/DRIER AIR TONIGHT AND TOMORROW AND THE MODELS DOREFLECT A DECREASE IN 1000-850 MB THICKNESS LEVELS TODAY THROUGHWEDNESDAY. INTERESTINGLY...HOWEVER...ALTHOUGH THE NAM5 BRINGS INMUCH DRIER AIR...IT ALSO IS THE MOST BULLISH ON THE CHANCE OFPRECIPITATION OVER THE LOCAL AREA SHOWING MANY SHOWERS MOVINGACROSS THE EASTERN PART OF THE ISLAND OVERNIGHT TUESDAY INTOWEDNESDAY. HAVE TEMPERED THE PREVIOUS VERY DRY FORECAST FOR THATPERIOD WITH THIS MODEL IN LIGHT OF CURRENT ACTIVITY AND UPSTREAMMOISTURE VISIBLE IN SATELLITE AND MIMIC IMAGERY...BUT KEPTWEDNESDAY AFTERNOON AND EVENING RELATIVELY DRY TO ACCOMMODATE THEBRIEF DECREASE IN MOISTURE. MOISTURE AND SHOWERS RETURN THURSDAY.

THE MAIN EFFECT OF THE UPPER LEVEL LOW APPEARS TO BE TO SUPPRESSTHE APPROACHING WAVES FROM THE EAST. WHEN THE UPPER LEVEL LOWBEGINS TO RETREAT FROM THE LEEWARD ISLANDS ON SUNDAY MORNING AND AWEAK TROUGH TO THE NORTH MIGRATES WEST AND TILTS NORTH-SOUTH OVERTHE MONA CHANNEL...FLOW AT THE SURFACE BECOMES QUITE SOUTHERLY AND SHOWERSSHOULD AGAIN EBB ON THE NORTH COAST. BUT EARLY NEXT WEEK THESOUTHERLY FLOW CONTINUES...TEMPERATURES RETURN TO THE LOWER 90SFOR THE NORTH COAST...AND MOISTURE MOVES AROUND THE ISLANDS FROMTHE SOUTHEAST.

THE CURRENT GFS FROM 02/00Z HAS THE LOW PRESSURE IN THEATLANTIC...NOW APPROACHING 40 DEGREES WEST LONGITUDE...RE-CURVINGON WEDNESDAY AND JOINING ON FRIDAY THE MASSIVE LOW THAT MOVESINTO THE NORTHEAST ATLANTIC ON THURSDAY.

&&

.AVIATION...MORNING PASSING SHOWERS WILL LIKELY AFFECT THE USVI/BVITERMINALS AS WELL AS TJSJ. MVFR/IFR CONDITIONS ARE POSSIBLE ASSHRA/TSRA ARE EXPECTED TO DEVELOP IN THE AFTERNOON HOURS ACROSS THEINTERIOR AND WESTERN SECTIONS OF PR...AFFECTING TJMZ AND POSSIBLYTHE VICINITY OF TJBQ..TJPS...AND TJSJ. INCREASING CLOUDINESS IN THEAFTERNOON WILL CAUSE MOUNTAIN OBSCURATIONS. WIND IS EXPECTED TOINCREASE AFTER 02/13Z...MAINLY EASTERLY WITH SEA BREEZE VARIATIONSAT 10 TO 15 KNOTS WITH HIGHER GUSTS.

&&

.MARINE...MODERATE TRADE WINDS AND SOME SWELL FROM TROPICAL STORMNADINE MAINTAIN 5 TO 6 FOOT SEAS IN OPEN WATERS AROUND THE ISLANDSTROUGH THURSDAY. WINDS AND SEAS DIMINISH LATE IN THE WEEK ANDOVER THE WEEKEND.

.SYNOPSIS...MID TO UPPER LEVEL RIDGE WILL REMAIN THE DOMINANTWEATHER FEATURE THROUGH AT LEAST WEDNESDAY. AN UPPER LEVEL TROUGHWILL APPROACH THE REGION THURSDAY AND FRIDAY.

&&

.DISCUSSION...SOME SHOWERS WITH ISOLATED THUNDERSTORMS DEVELOPEDTHIS AFTERNOON...FIRST...OVER THE SOUTH SECTION OF PUERTO RICO INTHE VICINITY OF PONCE...AND LATER OVER THE WESTERN INTERIOR ANDNORTHWEST SECTIONS OF PUERTO RICO. THIS ACTIVITY WAS ENHANCE BYTHE COMBINATION OF AVAILABLE MOISTURE AND LOCAL EFFECTS WITH SEABREEZE CONVERGENCE. MOST OF THIS ACTIVITY WILL DISSIPATED NEARSUNSET TONIGHT. THE MAIN WEATHER FEATURE WHICH IS AFFECTING THELOCAL REGION IS A MID TO UPPER LEVEL RIDGE WHICH WILL CONTINUE TODO SO THROUGH AT LEAST WEDNESDAY. IN FACT...LATEST COMPUTERGUIDANCE INDICATE A SLOT OF DRY AIR IS FORECAST TO MOVE ACROSS THEREGION WEDNESDAY AFTERNOON...WITH PRECIPITABLE WATER VALUESDROPPING TO NEAR 1.10 INCHES AND THETA-E VALUES AT 700MB AT 315K.IF THIS VERIFIES...WEDNESDAY MOST PROBABLY WILL BE THE DRIEST DAYOF THE WEEK...WITH ONLY SOME SHOWERS EXPECTED LATER IN THEAFTERNOON OVER THE SOUTHWEST SECTION OF PUERTO RICO.

THE EAST WIND FLOW WHICH IS PREVAILING AT THIS TIME...IS FORECASTTO SHIFT TO A MORE NORTHEASTERLY COMPONENT BY WEDNESDAYAFTERNOON...DUE TO AN APPROACHING UPPER LEVEL TROUGH. THIS TROUGHIS FORECAST TO MOVE VERY SLOWLY EAST OF THE LOCAL ISLANDS THROUGHNEXT WEEKEND. THIS FEATURE WILL PRODUCE SCATTERED SHOWERS OVER THECOASTAL WATERS. THE AFOREMENTIONED NORTHEAST WIND FLOW WILL MOVETHESE SHOWERS ALONG THE NORTHERN HALF OF PUERTO RICO AND THENORTHERN U.S. VIRGIN ISLANDS THURSDAY AND POSSIBLE FRIDAY. IN THELONG TERM...NO SIGNIFICANT WEATHER EVENTS ARE FORECAST TO AFFECTTHE REGION.

&&

.AVIATION...MVFR CONDITIONS EXPECTED TO PREVAIL OVER TRJMZ..ANDTJBQ THROUGH AT LEAST 01/22Z. ELSEWHERE...VFR CONDITIONS WILLPREVAIL WITH ONLY LIGHT PASSING SHOWERS EXPECTED.

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR RAPID RIVER RISES IN FOR THE FOLLOWING MUNICIPALITIES...

IN PUERTO RICO CIALES...HATILLO...JAYUYA...UTUADO...ARECIBO AND CAMUY

* UNTIL 600 PM AST

* AT 258 PM AST...DOPPLER RADAR INDICATED VERY HEAVY RAIN IN THEADVISORY AREA. LOCALIZED RAINFALL AMOUNTS OF ONE TO TWO INCHES AREPOSSIBLE THROUGH 600 PM AST.

EXCESSIVE RUNOFF WILL CAUSE FLOODING OF CREEKS AND STREAMS...ROADSAND ROADSIDE CULVERTS. THE HEAVY RAINS COULD ALSO TRIGGER ROCK ANDMUDSLIDES IN STEEP TERRAIN.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

* AT 249 PM AST...DOPPLER RADAR INDICATED VERY HEAVY RAIN IN THEADVISORY AREA. LOCALIZED RAINFALL AMOUNTS OF ONE TO TWO INCHES AREPOSSIBLE THROUGH 545 PM AST.

EXCESSIVE RUNOFF WILL CAUSE FLOODING OF CREEKS AND STREAMS...ROADSAND ROADSIDE CULVERTS. THE HEAVY RAINS COULD ALSO TRIGGER ROCK ANDMUDSLIDES IN STEEP TERRAIN.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

.SYNOPSIS...MID-UPPER LEVEL RIDGE WILL REMAIN THE DOMINANT WEATHERFEATURE THROUGH TODAY. UPPER LEVEL TROUGH ACROSS THE EAST CENTRALATLANTIC WILL CONTINUE TO BECOME MORE AMPLIFIED AND DIP FURTHERSOUTHWEST ACROSS THE LESSER ANTILLES BY TUESDAY...THEN RETROGRESSWESTWARD INTO THE EASTERN CARIBBEAN ON WEDNESDAY AND LINGER ACROSSTHE NORTHEAST CARIBBEAN THROUGH THEN END OF THE WEEK BEFORE FILLING.SURFACE HIGH PRESSURE RIDGE NORTH OF THE AREA ACROSS THE CENTRALATLANTIC...WILL CONTINUE TO BUILD AND SPREAD FURTHER WEST ANDSOUTHWEST ACROSS THE LOCAL REGION THROUGH THURSDAY. AN EASTERLYPERTURBATION/TUTT INDUCED JUST EAST OF THE LESSER ANTILLES WILLENTER THE EASTERN CARIBBEAN LATER TODAY...THEN MOVE MAINLY SOUTHOF THE REGION THROUGH TUESDAY. FURTHER EAST... A TROPICAL WAVEWITH AXIS NOW NEAR 44 WEST IS FORECAST TO CONTINUE WESTWARDS OVERTHE NEXT FEW DAYS...AND SHOULD ENTER THE EASTERN CARIBBEAN BYTHURSDAY OR FRIDAY.

&&

.DISCUSSION...FAIRLY STRONG UPPER RIDGE ACROSS THE REGION WILLCONTINUE TO LIMIT WIDESPREAD CONVECTION ACROSS THE ISLANDS AGAINTODAY. HOWEVER...LATEST SATELLITE IMAGERY AND DERIVED INTEGRATEDPRECIPITABLE WATER AS WELL AS WEATHER RADAR AND MODEL GUIDANCESUGGESTS...SUFFICIENT MOISTURE ADVECTION ACROSS THE REGION OVERTHE NEXT FEW DAYS...TO COMBINE WITH LOCAL AND DIURNAL EFFECTS TOPRODUCE PERIODS OF EARLY MORNING AND AFTERNOON CONVECTION EACHDAY.

WEAK LOW LEVEL PERTURBATION PREVIOUSLY MENTIONED APPROACHINGTHE WINDWARD ISLANDS WILL BRING ADDITIONAL MOISTURE TO REGIONDURING THE NEXT DAY OR SO. SHOWER ACTIVITY WILL BE ENHANCED BYTHE UPPER TROUGH WHICH WILL SAG SOUTHWEST ACROSS THE ISLAND CHAINOVER THE NEXT FEW DAYS. THE PREVAILING EASTERLIES WILL THEN TRANSPORTTHIS ENHANCED CONVECTION ACROSS THE LOCAL WATERS AND TOWARDS THEISLANDS THROUGH TUESDAY. THE ADDITIONAL MOISTURE ALONG WITH LOCALAND DIURNAL EFFECTS WILL CONTINUE TO TRIGGER DAYTIME CONVECTIONACROSS PARTS OF THE ISLANDS .

THE MOIST AND UNSTABLE PATTERN WILL CONTINUE THROUGH THE END OFTHE WEEK... AS A TROPICAL WAVE IS ALSO EXPECTED TO MOVE ACROSS THEEASTERN CARIBBEAN ON THURSDAY OR FRIDAY. THEREFORE...EXPECT HOT ANDUNSTABLE CONDITIONS EACH DAY WITH PERIODS OF LOCALLY HEAVY DOWNPOURSIN ISOLATED SPOTS DURING THE AFTERNOONS...ESPECIALLY ACROSS PARTS OFTHE INTERIOR AND WEST SECTION OF PUERTO RICO...AND TOO A LESSER DEGREEOVER PARTS OF THE CULEBRA...VIEQUES AND THE U.S. VIRGIN ISLANDS.

&&

.AVIATION...A WEAK TROF JUST EAST OF THE LEEWARD ISLANDS WILL SPREADSCT SHRA/TSRA ACROSS TNCM AND TKPK TIL 01/22Z WITH OCNL MVFR CONDS.SCT SHRA/TSRA WILL SPREAD ACROSS TIST AND TISX AFT 01/16Z WITH BRIEFMVFR PSBL AND MOV ONSHORE IN ERN PR AFT 02/00Z. SHRA/TSRA WILLDEVELOP IN WRN PR AFT 01/17Z WITH MTN OBSCURATIONS AND BRIEF MVFR ATTJMZ. LLVL WINDS BCMG EAST 5 TO 15 KT WITH SEA BREEZE VARIATIONSALONG THE COASTS.

&&

.CLIMATE...AT THE SAN JUAN AREA...SEPTEMBER 2012 ENDED AS THESIXTH DRIEST SEPTEMBER ON RECORD WITH 2.13 INCHES. THE DRIESTSEPTEMBER ON RECORD WAS SEPTEMBER 1940 WITH 1.49 INCHES. IN TERMSOF TEMPERATURES...SEPTEMBER 2012 ENDED AS THE WARMEST SEPTEMBERON RECORD WITH AN AVERAGE TEMPERATURE OF 84.9 DEGREES...TYINGSEPTEMBER 1995. AT CYRIL E. KING AIRPORT/SAINT THOMAS...SEPTEMBER2012 ENDED AS THE DRIEST SEPTEMBER ON RECORD WITH 0.92 INCHES.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR RAPID RIVER RISES IN FOR THE FOLLOWING MUNICIPALITIES...

IN PUERTO RICO LARES AND CAMUY

* UNTIL 400 PM AST

* AT 203 PM AST...DOPPLER RADAR INDICATED STRONG THUNDERSTORMS WITHHEAVY RAIN OVER THE ADVISORY AREA. OVER ONE INCH RAIN HAS ALREADYFALLEN AND ADDITIONAL RAINFALL AMOUNTS OF ONE TO TWO ARE POSSIBLETHROUGH 400 PM AST. THIS SHOWER ACTIVITY MAY CAUSE URBAN AND SMALLSTREAM FLOODING AS WELL AS RAPID RIVER RISES.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

.SYNOPSIS...MID-UPPER LEVEL RIDGE WILL REMAIN THE DOMINANT WEATHERFEATURE THROUGH MONDAY. MEANWHILE THE UPPER LEVEL TROUGH ACROSS THEEAST CENTRAL ATLANTIC WILL BECOME MORE AMPLIFIED AND DIP FURTHERSOUTHWEST ACROSS THE LESSER ANTILLES BY TUESDAY...THEN RETROGRESSWESTWARD INTO THE SOUTHEASTERN CARIBBEAN BY THE END OF THE UPCOMINGWEEK. SURFACE HIGH PRESSURE RIDGE NORTH OF THE AREA ACROSS THE CENTRALATLANTIC...WILL CONTINUE TO BUILD AND EXTEND SOUTHWEST ACROSS THELOCAL REGION THROUGH AT LEAST THE MIDDLE OF NEXT WEEK. FURTHER EASTOF THE LESSER ANTILLES...A TROPICAL WAVE WITH AXIS NEAR 37 WEST ISFORECAST TO CONTINUE WESTWARDS OVER THE NEXT SEVERAL DAYS...AND SHOULDENTER THE EASTERN CARIBBEAN DURING THE LATTER PART OF THE UPCOMINGWEEK.

&&

.DISCUSSION...FAIRLY STRONG UPPER RIDGE ACROSS THE REGION WILLSUPPRESS ANY SIGNIFICANT OR WIDESPREAD CONVECTION TODAY. HOWEVERSTILL EXPECT LOCAL AND DIURNAL EFFECTS TO HELP TRIGGER SOME SHORTLIVED AFTERNOON SHOWERS AND POSSIBLY ISOLATED THUNDERSTORMS MAINLYACROSS THE NORTHWEST SECTIONS OF PUERTO RICO UNDER THE CURRENTSOUTHEASTERLY WIND FLOW. MOSTLY FAIR WEATHER SKIES AND HOT CONDITIONSWILL DOMINATE ELSEWHERE INCLUDING OVER THE VIRGIN ISLANDS. AS THEATLANTIC HIGH REESTABLISHES ITSELF NORTH OF THE AREA...LOCAL WINDSWILL GRADUALLY BECOME MORE EASTERLY DURING THE NEXT 24 TO 36 HOURSOF SO WITH A SLIGHT TIGHTENING OF THE SURFACE PRESSURE GRADIENT.LATEST GFS MODEL GUIDANCE INITIATED WELL AND CONTINUED TO SUGGESTSUBSIDENCE INVERSION TO HOLD FOR THE NEXT FEW DAYS...WITH A GRADUALDECREASE IN PWAT VALUES ACROSS THE AREA BEGINNING ON MONDAY ANDCONTINUING THROUGH WEDNESDAY. THIS WILL BE FOLLOWED BY INCREASINGTROPICAL MOISTURE ONCE AGAIN DURING THE LATTER PART OF THE WEEK ASTHE PREVIOUSLY MENTIONED TROPICAL WAVE ENTERS THE SOUTHEASTERN CARIBBEAN.UNTIL THEN EXPECT MOSTLY ISOLATED TO SCATTERED LOCAL AND DIURNALLYINDUCED CONVECTION EACH DAY WITH ONLY A FEW EARLY MORNING PASSINGPASSING SHOWERS IN SOME COASTAL AREAS FROM TIME TO TIME. NO SIGNIFICANTOR WIDESPREAD RAINFALL IN SIGHT FOR NOW.

&&

.AVIATION...MAINLY VFR CONDITIONS WILL PREVAIL ACROSS ALL OF THELOCAL FLYING AREA FOR THE NEXT 24 HRS WITH AN ISOLATED SHOWER OR TWOIN AND AROUND TIST/TISX. AFT 30/17Z...SHRA/TSRA EXPECTED TO DEVELOPACROSS NW PR...RESULTING IN BRIEF MVFR CONDITIONS AT TJBQ THROUGHABOUT 30/21Z. WINDS MAINLY FROM THE SOUTHEAST AT 10-15 KT.

&&

CLIMATE...SEPTEMBER 2012 AT THE SJU LUIS MUNOZ MARIN INTERNATIONALAIRPORT WILL END AS THE WARMEST SEPTEMBER ON RECORD. SEPTEMBER 2012 HAS NOWMOVED INTO FIRST PLACE WITH AN AVG TEMP OF 85 DEGREES FAHRENHEITSO FAR. ANOTHER HOT DAY IS EXPECTED TODAY WITH TEMPERATURES POSSIBLYIN THE LOW 90S WHICH COULD CHALLENGE TODAYS RECORD OF 94 DEGREES. INTERMS OF RAINFALL...SEPTEMBER 2012 WILL END AS AS THE SECOND DRIESTSEPTEMBER ON RECORD WITH A TOTAL OF 1.66 INCHES OF RAIN SO FAR.VERY LITTLE ADDITIONAL RAIN IS EXPECTED TODAY.

AT THE CYRIL E. KING AIRPORT IN ST. THOMAS...SEPTEMBER 2012 CURRENTLY RANKSAS THE DRIEST SEPTEMBER ON RECORD WITH 0.92 INCHES OF RAIN. THE SECONDDRIEST SEPTEMBER ON RECORD WAS IN 1986 WITH 1.08 INCHES AND THIRD WAS 1987WITH 1.42 INCHES. VERY LITTLE ADDITIONAL RAIN IF ANY IS EXPECTEDTODAY.

.SYNOPSIS...MID-UPPER LEVEL RIDGE WILL PREVAIL THROUGH MONDAY. UPPERLEVEL TROUGH ACROSS THE EASTERN CENTRAL ATLANTIC WILL EXTEND A TROUGHINTO THE AREA TUESDAY THROUGH THE END OF NEXT WEEK.

&&

.DISCUSSION...SHOWER AND THUNDERSTORM ACTIVITY THIS AFTERNOON WASLIMITED TO THE NORTHWEST PART OF PUERTO RICO. AS 2 PM...MOST OFPUERTO RICO AND THE U.S. VIRGIN ISLANDS WERE UNDER MOSTLY SUNNYSKIES WITH MAXIMUM TEMPERATURES IN THE UPPER 80S TO LOW 90S. ASOUTH TO SOUTHEAST WIND FLOW BETWEEN THE SURFACE UP TO 20K FEETPER LATEST 12Z TJSJ SOUNDING...IS PROMOTING THIS HOT TEMPERATURESMAINLY OVER THE NORTHERN HALF OF PUERTO RICO. THESE CONDITIONS AREEXPECTED TO PREVAIL FOR AT LEAST ONE MORE DAY...BEFORE A SURFACEHIGH PRESSURE...OVER THE CENTRAL ATLANTIC SHIFT WEST...AND A MOREEASTERLY COMPONENT IN THE WIND FLOW ESTABLISH OVER THE REGION.

IN TERM OF CHANCES OF PRECIPITATION FOR THE LOCAL AREA...A DRIERAIR MASS IS EXPECTED TO MOVE OVER THE REGION TOMORROW...LIMITINGEVEN MORE THE CHANCES FOR SHOWER ACTIVITY OVER THE REGION. FORTUESDAY...THE PROXIMITY OF AN UPPER LEVEL TROUGH IS FORECAST TOBRING BETTER MOISTURE CONTENT OVER THE REGION...WHICH WILL ENHANCETHE DEVELOPMENT OF AFTERNOON CONVECTION EACH DAY NEXT WEEK. IN THELONG TERM...AT THIS TIME...NO SIGNIFICANT WEATHER EVENTS AREFORECAST TO AFFECT THE REGION.

.FIRE WEATHER...SEP 2012 WILL END AS THE WARMEST AND ONE OF THEDRIEST SEPTEMBERS ON RECORD FOR A LOT OF PLACES ACROSS THE ISLAND.FUELS ACROSS THE SOUTH AND EAST HAVE DRIED OUT SIGNIFICANTLY OVERTHE PAST 30 DAYS AND MIGHT SUPPORT FIRE. RECORD BREAKINGTEMPERATURES IN THE MID 90S ARE EXPECTED TOMORROW WHILE MID-UPPERLEVEL RIDGE ERODES LOW LEVEL MOISTURE RAPIDLY. PRECIPITABLE WATERVALUES WILL DROP TO 1.5 INCHES WHICH ARE BELOW THE 25TH PERCENTILEFOR THIS TIME OF THE YEAR. THE VERY HOT TEMPERATURES COMBINED WITHTHE LOW MOISTURE CONTENT WILL RESULT IN VERY LOW RH VALUES. WINDSWILL BE THE SOUTHEAST AT 15MPH WITH GUSTS TO 25 MPH. CONDITIONSIMPROVE MON AS MOISTURE INCREASES AND TEMPS DROP A FEW DEGS ASWINDS SHIFT TO A MORE EASTERLY DIRECTION.

.CLIMATE...SEP 2012 AT THE SJU LMM INTL ARPT WILL END AS THE WARMESTSEP ON RECORD. SEP 2012 HAS NOW MOVED SOLELY INTO FIRST PLACE ANDTEMPS IN THE MID 90S TODAY AND ESPECIALLY TOMORROW WILL ONLY HELPIN MOVING FURTHER APART FROM SEP 1995. IN TERMS OF RAINFALL...SEP2012 CURRENTLY RANKS AS THE SECOND DRIEST SEP ON RECORD WITH ATOTAL OF 1.66 INCHES OF RAIN SO FAR. THE THIRD DRIEST SEP ONRECORD IS 1987 WITH 1.73 INCHES AND FOURTH IS 2006 WITH 1.78INCHES. THERE IS STILL A CHANCE TO PICKUP ANOTHER QUARTER INCH OFRAIN BEFORE THE MONTH ENDS WHICH COULD ALTER THE CURRENT RANKS BUTIT CAN BE SAID WITH DEFINITE CERTAINTY THAT SEP WILL END IN THETOP FIVE DRIEST SEPTEMBERS ON RECORD.

AT THE CYRIL E. KING ARPT IN ST. THOMAS...SEP 2012 CURRENTLY RANKSAS THE DRIEST SEP ON RECORD WITH 0.92 INCHES OF RAIN. THE SECONDDRIEST SEP ON RECORD WAS IN 1986 WITH 1.08 INCHES AND THIRD WAS 1987WITH 1.42 INCHES. THERE IS STILL A CHANCE TO PICKUP ANOTHER QUARTEROF AN INCH OF RAIN WHICH COULD ALTER THE CURRENT RANKS BUT IT CAN BESAID WITH DEFINITE CERTAINTY THAT SEP WILL END IN THE TOP THREEDRIEST SEPTEMBERS ON RECORD.

.SYNOPSIS...SATELLITE ANALYSIS AND COMPUTER MODEL GUIDANCE DEPICTEDAN UPPER LEVEL TROUGH EAST NORTHEAST OF THE LESSER ANTILLES THISMORNING. THIS FEATURE WILL MOVE WEST WHILE FILLING DURING THE NEXTFEW DAYS. AN UPPER LEVEL RIDGE WILL CONTINUE AS THE MAIN WEATHERFEATURE ACROSS THE LOCAL REGION UNTIL AT LEAST MONDAY. A RELATIVELYUNSTABLE WEATHER PATTERN WILL PREVAIL ACROSS THE REGION UNTIL ATLEAST SATURDAY.

&&

.DISCUSSION...PARTLY CLOUDY SKIES PREVAILED ACROSS PUERTO RICOOVERNIGHT AND EARLY THIS MORNING. SCATTERED SHOWERS AND A FEWTHUNDERSTORMS WERE OBSERVED ACROSS THE ATLANTIC AND CARIBBEANCOASTAL WATERS...WITH FEW OF THEM AFFECTING THE EASTERN AND SOUTHERNSECTIONS OF PUERTO RICO AS WELL AS VIEQUES...CULEBRA AND THE U.S.VIRGIN ISLANDS FROM TIME TO TIME. SOME PERIODS OF MODERATE RAINFALLWAS OBSERVED ACROSS SOUTHEASTERN SECTIONS OF PUERTO RICO.

AN UPPER LEVEL TROUGH EAST AND NORTHEAST OF THE LESSER ANTILLES ISEXPECTED TO MOVE WESTWARD WHILE FILLING DURING THE NEXT FEW DAYS. ANUPPER LEVEL RIDGE IS EXPECTED TO CONTINUE AS THE MAIN WEATHERFEATURE ACROSS THE LOCAL ISLANDS UNTIL AT LEAST MONDAY. A RELATIVELYMOIST AND UNSTABLE SOUTHEAST LOW LEVEL WIND FLOW WILL CONTINUE TOTRANSPORT PATCHES OF MOISTURE ACROSS THE LOCAL ISLANDS FROM TIME TOTIME FOR THE NEXT SEVERAL DAYS. UNDER THE INFLUENCE OF THE SOUTHEASTLOW TO MID LEVEL FLOW THIS MOISTURE IN COMBINATION WITH LOCALEFFECTS AND MARGINAL UPPER LEVEL VENTILATION...WILL INDUCE A FAIRLYACTIVE WEATHER ACROSS THE REGION...WITH SHOWERS AND THUNDERSTORMSDEVELOPING MAINLY OVER THE CORDILLERA CENTRAL OF PUERTO RICO EARLYIN THE AFTERNOON...THEN MOVING ACROSS THE NORTH AND NORTHWESTCOASTAL AREAS LATER IN THE AFTERNOON.

&&

.AVIATION...VFR CONDS WILL PREVAIL AT ALL TAF SITES. HOWEVER QUICKPASSING -SHRA/SHRA EMBEDDED IN THE L/LVL ESE FLOW WILL MOVEACROSS THE REGIONAL WATERS AND AFFECT PARTS OF THE SOUTH AND EASTCOASTAL SECTIONS OF THE ISLANDS TIL 29/15Z. THESE SHOWERS WILLBRIEFLY AFFECT TIST...TISX AND TJPS FM TIME TO TIME. AFTNCONVECTION WILL DEVELOP ONCE AGAIN ACROSS CENTRAL...NORTHERN ANDNORTH WESTERN PR. AS A RESULT...EXPECT MTN TOP OBSCR AND PERIODSOF MVFR/IFR NEAR TJMZ AND TJBQ BTW 29/17 AND 29/21Z.

ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE POSSIBLE IN THEADVISORY AREA WITH THE HEAVIEST RAINS IN CENTRAL QUEBRADILLAS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

.SYNOPSIS...HIGH PRESSURE SYSTEM WILL REMAIN OVER THE REGIONTHROUGH AT LEAST MID NEXT WEEK. UPPER LEVEL TROUGH LOCATEDNORTHEAST OF THE LESSER ANTILLES...WILL MOVE WEST NEXT FEW DAYS.

&&

.DISCUSSION...SHOWERS WITH ISOLATED STRONG THUNDERSTORMS DEVELOPEDTHIS AFTERNOON OVER THE CORDILLERA CENTRAL. THE HEAVIESTRAINFALL OCCURRED OVER THE WESTERN INTERIOR SECTION OF PUERTORICO WITH OVER THREE INCHES PER HOUR REPORTED IN THE MUNICIPALITYOF LARES. THIS ACTIVITY WAS ASSOCIATED WITH THE COMBINATION OFDAYTIME HEATING...WITH AVAILABLE MOISTURE AND OROGRAPHIC EFFECTS.THIS ACTIVITY WILL DISSIPATED NEAR SUNSET.

THE SAME WEATHER PATTERN...WITH SHOWERS AND THUNDERSTORMSARE EXPECTED EACH AFTERNOON NEXT FEW DAYS. AN UPPER LEVEL RIDGEWILL CONTINUE TO DOMINATE THE REGION THROUGH AT LEAST MID NEXTWEEK. THIS WILL MAINTAIN MOSTLY SUNNY SKIES DURING THE MORNINGHOURS ACROSS THE LOCAL ISLANDS...WITH ONLY PASSING SHOWERSEXPECTED. AN UPPER LEVEL TROUGH LOCATED NORTHEAST OF THEAREA...WILL MOVE SLOWLY WEST NEXT FEW DAYS. THIS TROUGH ISEXPECTED TO MOVE IN A MORE FAVORABLE AREA FOR SHOWER DEVELOPMENTLOCALLY...MID NEXT WEEK. IN THE LONG TERM...NO SIGNIFICANT WEATHEREVENTS ARE FORECAST TO AFFECT THE REGION.

&&

.AVIATION...AFTERNOON SHRA/TSRA ACROSS THE NW SECTIONS OF PUERTORICO WILL AFFECT THE AREAS AROUND TJBQ...THEREAFTER...VFR CONDITIONSWILL PREVAIL ACROSS ALL TAF SITES THIS EVENING AND OVERNIGHT. WINDSWILL BECOME LIGHT AND VARIABLE TONIGHT AT THE SURFACE. SHRA/TSRA AREONCE AGAIN EXPECTED TOMORROW AFTERNOON ACROSS THEINTERIOR....NORTHERN...AND NORTHWESTERN PR.

AT 316 PM AST...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TOINDICATE HEAVY RAIN OVER THE GUAJATACA RIVER BASIN IN THE WARNEDAREA. AT 3:20 PM AST THE RIVER GAGE ON THE GUAJATACA AT LARES WASREGISTERING 16.24 FEET WHICH RAISES THE RIVER OUT OF ITS BANKS INLARES AND FLOODS HOMES IN BARRIO SEBORUQUILLO.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MOVE TO HIGHER GROUND BEFORE YOUR ESCAPE ROUTE IS CUT OFF. THIS HASBEEN A VERY LARGE STORM WITH VERY HEAVY RAIN AND THE RIVER ISEXPECTED TO CONTINUE RISING.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALLCREEKS AND STREAMS...HIGHWAYS AND UNDERPASSES. ADDITIONALLY...COUNTRYROADS AND FARMLANDS ALONG THE BANKS OF CREEKS...STREAMS AND OTHER LOWLYING AREAS ARE SUBJECT TO FLOODING.

&&

LAT...LON 1837 6699 1839 6688 1830 6684 1827 6692

$$

SNELL

ADDITIONAL INFORMATION CAN BE FOUND AT /USE LOWER CASE LETTERS/: HTTP://WWW.WEATHER.GOV/SANJUAN

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR RAPID RIVER RISES IN FOR THE FOLLOWING MUNICIPALITIES...

IN PUERTO RICO LARES...UTUADO AND SAN SEBASTIAN

* UNTIL 430 PM AST

* AT 230 PM AST...DOPPLER RADAR INDICATED STRONG THUNDERSTORMS WITHHEAVY RAIN OVER THE ADVISORY AREA. OVER ONE INCH RAIN HAS ALREADYFALLEN AND ADDITIONAL RAINFALL AMOUNTS OF ONE TO TWO ARE POSSIBLETHROUGH 430 PM AST. THIS SHOWER ACTIVITY MAY CAUSE URBAN AND SMALLSTREAM FLOODING AS WELL AS RAPID RIVER RISES.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

.SYNOPSIS...COMPUTER MODEL GUIDANCE DEPICTED AN UPPER LEVEL TROUGHACROSS THE REGION...EXTENDING SOUTH SOUTHWESTWARD TO THE LESSERANTILLES FROM THE UPPER LOW ACROSS THE CENTRAL ATLANTIC. AN UPPERLEVEL RIDGE WILL DEVELOP ACROSS THE LOCAL ISLANDS DURING THEWEEKEND. A RELATIVELY UNSTABLE WEATHER PATTERN WILL PREVAIL ACROSSTHE REGION UNTIL AT LEAST SATURDAY.

&&

.DISCUSSION...VARIABLY CLOUDY SKIES PREVAILED ACROSS PUERTO RICOOVERNIGHT AND EARLY THIS MORNING. SCATTERED TO NUMEROUS SHOWERS ANDA FEW THUNDERSTORMS DOTED THE ATLANTIC AND CARIBBEAN COASTAL WATERSOVERNIGHT AND EARLY THIS MORNING...WITH FEW OF THEM AFFECTING THEEASTERN AND SOUTHEASTERN SECTIONS OF PUERTO RICO AS WELL ASVIEQUES...CULEBRA AND THE U.S. VIRGIN ISLANDS FROM TIME TO TIME.SOME PERIODS OF MODERATE RAINFALL WAS OBSERVED ACROSS THELOCAL ISLANDS.

UPPER LEVEL TROUGH EXTENDING SOUTH SOUTHWESTWARD ACROSS THE LESSERANTILLES FROM AN UPPER LOW ACROSS THE CENTRAL ATLANTIC. LOW LEVELPERTURBATIONS/REFLECTIONS ASSOCIATED WITH THE AFOREMENTIONED UPPERTROUGH WILL MAINTAIN AN UNSTABLE AIR MASS ACROSS THE LOCAL REGIONUNTIL AT LEAST SATURDAY. DEEP MOISTURE IN COMBINATION WITH THEUNSTABLE ATMOSPHERE...LOCAL EFFECTS AND MARGINAL UPPER LEVELVENTILATION...WILL INDUCE A FEW MORE DAYS OF FAIRLY ACTIVE WEATHERACROSS THE REGION...WITH SHOWERS AND THUNDERSTORMS MAINLY OVERTHE CENTRAL PART OF PUERTO RICO EARLY THIS AFTERNOON...THEN ACROSSTHE NORTH AND NORTHWEST COASTAL AREAS LATER IN THE AFTERNOONUNDER THE INFLUENCE OF A SOUTHEAST LOW TO MID LEVEL FLOW.

AND UPPER LEVEL RIDGE WILL BUILD ACROSS THE REGION SATURDAY ANDSUNDAY WITH SOME DRIER...MORE STABLE AND "WARMER" AIR MASS GENERALLYEXPECTED FOR SUNDAY AND MONDAY.

&&

.AVIATION...VFR CONDS WILL PREVAIL AT ALL TAF SITES. HOWEVER QUICKPASSING -SHRA/SHRA EMBEDDED IN THE L/LVL ESE FLOW WILL MOVEACROSS THE REGIONAL WATERS AND AFFECT PARTS OF THE SOUTH AND EASTCOASTAL SECTIONS OF THE ISLANDS TIL 28/15Z. THESE SHOWERS WILLBRIEFLY AFFECT TIST...TISX AND TJPS FM TIME TO TIME. AFTNCONVECTION WILL DEVELOP ONCE AGAIN ACROSS CENTRAL...NORTHERN ANDNORTH WESTERN PR. AS A RESULT...EXPECT MTN TOP OBSCR AND PERIODSOF MVFR/IFR NEAR TJMZ AND TJBQ BTW 28/17 AND 28/21Z.

AREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE SAN JUAN PRISSUED BY NATIONAL WEATHER SERVICE MIAMI FL726 PM AST THU SEP 27 2012

.AVIATION...VFR AND LIGHT WINDS WILL PREVAIL. A FEW SHOWERS AREPOSSIBLE IN THE VICINITY OF THE EASTERN TERMINALS THROUGHOUT THENIGHT. ON FRIDAY, SHRA/TSRA WILL AGAIN CONCENTRATE OVER THEINTERIOR/WEST DURING THE AFTERNOON WITH TSRA LIKELY IN THE VICINITYOF KJMZ IN THE AFTERNOON, SO INCLUDED VCTS THERE FRI AFTERNOON.WINDS WILL BECOME EAST 5-10 KT FRI EXCEPT WESTERLY AT KJMZ./GREGORIA

&&

.DISCUSSION...

A TROPICAL WAVE JUST WEST OF HISPANIOLA WILL CONTINUE MOVING WESTTONIGHT. IN ITS WAKE A PLUME OF MOISTURE EXTENDS EASTWARD ACROSSPUERTO RICO AND THE U.S. VIRGIN ISLANDS...WITH THE 12Z JSJSOUNDING INDICATING A PWAT IN EXCESS OF TWO INCHES. THECOMBINATION OF THE MOISTURE SOURCE AND A LOW LEVEL INVERTED TROUGHEXTENDING ACROSS THE ISLANDS WILL CONTINUE TO FAVOR SHOWERS ANDTHUNDERSTORMS ACROSS THE REGION THIS AFTERNOON AND EVENING...WITHMOST OF THE ACTIVITY EXPECTED ACROSS PUERTO RICO WITHCULEBRA...VIEQUES AND THE U.S. VIRGIN ISLANDS EXPECTING PASSINGSHOWERS. REPORTED ACCUMULATIONS SO FAR INDICATE NEAR 4 INCHES OFRAIN HAVE BEEN REPORTED NEAR GURABO AND VILLALBA WITH URBAN FLOODSTATEMENTS ISSUED FOR THESE AREAS EARLIER.

THE RECENT GUIDANCE INDICATES A LIGHT TO MODERATE SOUTHEASTERLYFLOW WILL PREVAIL ACROSS THE REGION FRIDAY AND SATURDAY. THESOUTHEASTERLY FLOW AND SUFFICIENT MOISTURE ACROSS THE REGION WILL FAVORCHANCES OF SHOWERS AND THUNDERSTORMS MAINLY ACROSS PUERTORICO...WITH THE MOST FAVORED AREAS OF CONVECTION UNDER THIS FLOWREGIME BEING THE NORTHERN AND NORTHWESTERN PORTIONS OF THEISLAND...WITH NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMSINDICATED IN THE FORECAST WITH MORE SCATTERED ACTIVITY EXPECTEDELSEWHERE. BY SUNDAY SOME DRIER AIR IS FORECAST TO ENTER THEREGION WITH A RIDGE BUILDING AT THE UPPER LEVELS..WITH CHANCES OFSHOWERS AND THUNDERSTORMS DIMINISHING.

&&

.MARINE...

THE FORECAST FOR THE ATLANTIC WATERS IS FOR SEAS RANGING FROM NEAR3 TO 5 FEET TONIGHT INTO THE WEEKEND WITH A LIGHT TO MODERATE EASTTO SOUTHEAST FLOW FORECAST ACROSS THE REGION. FOR THE CARIBBEANWATERS GOING INTO THE WEEKEND SEAS FROM 1 TO 3 FEET ARE FORECASTTHEN INCREASING TO 3 TO 4 FEET INTO SUNDAY.

AREA FORECAST DISCUSSIONNATIONAL WEATHER SERVICE SAN JUAN PRISSUED BY NATIONAL WEATHER SERVICE MIAMI FL438 PM AST THU SEP 27 2012

.DISCUSSION...

A TROPICAL WAVE JUST WEST OF HISPANIOLA WILL CONTINUE MOVING WESTTONIGHT. IN ITS WAKE A PLUME OF MOISTURE EXTENDS EASTWARD ACROSSPUERTO RICO AND THE U.S. VIRGIN ISLANDS...WITH THE 12Z JSJSOUNDING INDICATING A PWAT IN EXCESS OF TWO INCHES. THECOMBINATION OF THE MOISTURE SOURCE AND A LOW LEVEL INVERTED TROUGHEXTENDING ACROSS THE ISLANDS WILL CONTINUE TO FAVOR SHOWERS ANDTHUNDERSTORMS ACROSS THE REGION THIS AFTERNOON AND EVENING...WITHMOST OF THE ACTIVITY EXPECTED ACROSS PUERTO RICO WITHCULEBRA...VIEQUES AND THE U.S. VIRGIN ISLANDS EXPECTING PASSINGSHOWERS. REPORTED ACCUMULATIONS SO FAR INDICATE NEAR 4 INCHES OFRAIN HAVE BEEN REPORTED NEAR GURABO AND VILLALBA WITH URBAN FLOODSTATEMENTS ISSUED FOR THESE AREAS EARLIER.

THE RECENT GUIDANCE INDICATES A LIGHT TO MODERATE SOUTHEASTERLYFLOW WILL PREVAIL ACROSS THE REGION FRIDAY AND SATURDAY. THESOUTHEASTERLY FLOW AND SUFFICIENT MOISTURE ACROSS THE REGION WILL FAVORCHANCES OF SHOWERS AND THUNDERSTORMS MAINLY ACROSS PUERTORICO...WITH THE MOST FAVORED AREAS OF CONVECTION UNDER THIS FLOWREGIME BEING THE NORTHERN AND NORTHWESTERN PORTIONS OF THEISLAND...WITH NUMEROUS SHOWERS AND SCATTERED THUNDERSTORMSINDICATED IN THE FORECAST WITH MORE SCATTERED ACTIVITY EXPECTEDELSEWHERE. BY SUNDAY SOME DRIER AIR IS FORECAST TO ENTER THEREGION WITH A RIDGE BUILDING AT THE UPPER LEVELS..WITH CHANCES OFSHOWERS AND THUNDERSTORMS DIMINISHING.

&&

.MARINE...

THE FORECAST FOR THE ATLANTIC WATERS IS FOR SEAS RANGING FROM NEAR3 TO 5 FEET TONIGHT INTO THE WEEKEND WITH A LIGHT TO MODERATE EASTTO SOUTHEAST FLOW FORECAST ACROSS THE REGION. FOR THE CARIBBEANWATERS GOING INTO THE WEEKEND SEAS FROM 1 TO 3 FEET ARE FORECASTTHEN INCREASING TO 3 TO 4 FEET INTO SUNDAY.

.SYNOPSIS...COMPUTER MODEL GUIDANCE DEPICTED TWO WEAK TUTT LOWS...ONE ACROSS THE CENTRAL CARIBBEAN JUST OVER CUBA AND ANOTHER ONENORTHEAST OF THE REGION. BOTH SYSTEMS ARE EXPECTED TO FILLED RAPIDLYTODAY AS AN UPPER LEVEL RIDGE BUILDS AND EXTENDS ACROSS THE LOCALAREA FOR THE NEXT SEVERAL DAYS. A RELATIVELY UNSTABLE WEATHERPATTERN WILL PREVAIL ACROSS THE REGION UNTIL AT LEASTFRIDAY.

&&

.DISCUSSION...VARIABLY CLOUDY SKIES PREVAILED ACROSS PUERTO RICOOVERNIGHT AND EARLY THIS MORNING. SCATTERED TO NUMEROUS SHOWERS ANDA FEW THUNDERSTORMS DOTED THE ATLANTIC AND CARIBBEAN COASTAL WATERSOVERNIGHT AND EARLY THIS MORNING...WITH FEW OF THEM AFFECTING THENORTHERN AND EASTERN SECTIONS OF PUERTO RICO FROM TIME TO TIME. SOMEPERIODS OF MODERATE RAINFALL WAS OBSERVED ACROSS THE NORTHEASTERNAND EASTERN SECTIONS OF THE ISLAND.

A VERY WEAK TUTT LOWS...ONE ACROSS CENTRAL CARIBBEAN AND ANOTHER ONENORTHEAST OF PUERTO RICO WILL CONTINUE TO FILL AS AN UPPER LEVELRIDGE BUILDS ACROSS THE REGION TODAY AND FOR THE NEXT SEVERAL DAYS.HOWEVER...DEEP MOISTURE IN COMBINATION WITH AN UNSTABLEATMOSPHERE...LOCAL EFFECTS AND UPPER LEVEL VENTILATION ASSOCIATEDWITH THE AFOREMENTIONED DEVELOPING UPPER LEVEL RIDGE...WILL YIELD AFEW MORE DAYS OF FAIRLY ACTIVE WEATHER ACROSS THE LOCAL AREA...WITHSHOWERS AND THUNDERSTORMS MAINLY OVER THE SOUTH PART OF PUERTO RICOTODAY...THEN ACROSS THE NORTH COAST ON FRIDAY AND SATURDAY UNDER THEINFLUENCE OF A SOUTHEAST LOW TO MID LEVEL FLOW. AN OVERALLDRIER...MORE STABLE AND "WARMER" AIR MASS IS GENERALLY EXPECTED FORSATURDAY...SUNDAY AND MONDAY.

&&

.AVIATION...VFR CONDS ARE EXPECTED TO PREVAIL ACROSS ALL TAF SITESOVERNIGHT. HOWEVER...SCT -SHRA EMBEDDED IN THE LLVL NELY FLOW MAYAFFECT TIST...TISX AND TJSJ FM TIME TO TIME. AFTERNOON CONVECTIONWILL DEVELOP ONCE AGAIN TOMORROW ACROSS CENTRAL...SOUTH AND WESTERNPR. AS A RESULT...EXPECT MOUNTAIN OBSCURATION AND PERIODS OFMVFR/IFR CONDS NEAR TJMZ AND TJPS BTWN 27/17 AND 27/21Z. EVENINGTJSJ RAOB SHOWED MAINLY NE WINDS AT 10 KTS OR LESS BLW 20 KFT.

DISCUSSION...DEEP MOISTURE IN COMBINATION WITH AN UNSTABLEATMOSPHERE...LOCAL EFFECTS AND UPPER LEVEL VENTILATION ASSOCIATEDWITH THE AFOREMENTIONED UPPER RIDGE WILL YIELD A FEW MORE DAYS OFFAIRLY ACTIVE WEATHER ACROSS THE LOCAL AREA...WITH SHOWERS ANDTHUNDERSTORMS CONCENTRATING OVER THE SOUTH PART OF PUERTO RICOTHURSDAY...THEN ACROSS THE NORTH COAST ON FRIDAY AND SATURDAY INSOUTHEAST LOW TO MID LEVEL FLOW. AN OVERALL DRIER...MORE STABLEAND "WARMER" AIR MASS IS GENERALLY EXPECTED FOR SUNDAY ANDMONDAY.

* AT 158 PM AST...DOPPLER RADAR INDICATED STRONG THUNDERSTORMS WITHMODERATE TO HEAVY HEAVY RAIN OVER THE ADVISORY AREA. OVER ONE INCHRAIN HAS ALREADY FALLEN AND ADDITIONAL RAINFALL AMOUNTS OF ONE TOTWO ARE POSSIBLE THROUGH 500 PM AST. THIS WILL CAUSE RAPID RIVERRISES AND FLOODING IN URBAN AREAS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR RAPID RIVER RISES IN FOR THE FOLLOWING MUNICIPALITIES...

IN PUERTO RICO GUAYANILLA...JUANA DIAZ...PENUELAS AND PONCE

* UNTIL 345 PM AST

* AT 1245 PM AST...DOPPLER RADAR INDICATED STRONG THUNDERSTORMS WITHVERY HEAVY RAIN OVER THE ADVISORY AREA. OVER ONE INCH RAIN HASALREADY FALLEN AND ADDITIONAL RAINFALL AMOUNTS OF ONE TO TWO AREPOSSIBLE THROUGH 345 PM AST.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

.SYNOPSIS...TUTT AXIS EXTENDING FROM HAITI SWD TO PANAMA WILLCONTINUE TO MIGRATE WEST WITH MID-UPPER LEVEL RIDGE EXPECTED TOBUILD OVER THE AREA OVER THE NEXT 24 HRS. RIDGE WILL HOLD THROUGHEARLY NEXT WEEK WHEN IT WILL START TO MIGRATE WEST AS IT YIELDS TOA DIGGING UPPER TROUGH ACROSS THE CNTRL ATLC NEXT WEEK.

&&

.DISCUSSION...DEEP MOISTURE IN COMBINATION WITH AN UNSTABLEATMOSPHERE AND UPPER LEVEL VENTILATION ASSOCIATED WITH BUILDINGUPPER RIDGE WILL YIELD SVRL DAYS OF ACTIVE WX THE MOST ACTIVEWEATHER WE HAVE SEEN SO FAR THIS MONTH. BEST RAINFALL ACCUMULATIONSLOOK TO BE THU AND FRI WHEN THE STEERING FLOW WILL BE WEAKEST.TODAY AND THU CONVECTION WILL CONCENTRATE IN THE SOUTH BUT ON FRISTEERING FLOW TURNS SOUTHEASTERLY WITH CONVECTION SHIFTING TO THENORTH COAST.

ON SAT...UPPER TROUGH ACROSS THE WRN CARIBBEAN INTERACTING WITHBROAD SFC LOW AND TROPICAL WAVE OVER THE SOUTH CNTRL CARIBBEAN SEA WILLRESULT IN A SIG HEAVY RAINFALL EVENT FOR HISPANIOLA AND JAMAICA.H85 FCST FIELDS FROM GFES SHOW TWO SEPARATE AREAS OF LIFT ONEAIMED AT JAMAICA AND ANOTHER ONE INTO THE FAR ERN DOMINICANREPUBLIC. CONVECTION WILL START TO BUILD ACROSS THE MONA CHANNELSAT MORNING AND AFFECT PORTIONS OF WESTERN PR. WHILE THERE SHOULDBE ACTIVE WX RAINFALL ACCUMULATIONS ARE NOT EXPECTED TO BEEXCESSIVE.

DEEP MOISTURE GETS SHUNTED AWAY FROM THE AREA SUN WITH HOTTEMPERATURES RETURNING TO THE AREA AND IMPROVING WEATHERCONDITIONS.

&&

.AVIATION...MOSTLY VFR CONDS ARE EXPECTED TO PREVAIL ACROSS ALL TAFSITES THIS MORNING. HOWEVER...SHRA EMBEDDED IN THE LLVL NELY FLOWMAY AFFECT TIST...TISX AND TJSJ FROM TIME TO TIME UNTIL 26/15Z. AFTER26/16Z THUNDERSTORMS WILL DEVELOP ACROSS THE INTERIOR ANDWESTERN SECTIONS OF PUERTO RICO...AFFECTING THE AREAS AROUND TJMZAND POSSIBLY TJPS. TJSJ 26/00 SOUNDING SHOWED MAINLY NE WINDS AT 15KTS OR LESS BLW 25 KFT.

&&

.MARINE...PULSES OF NORTHEAST SWELLS WILL AFFECT THE COASTALWATERS OVER THE NEXT FIVE DAYS. ACTIVE WX IS EXPECTED ACROSS THEMONA PASSAGE SAT WHICH MAY REQUIRE SMWS.

&&

.CLIMATE...RELATIVELY COOL NEXT 3-4 DAYS DUE TO BETTER CHANCES OFRAIN AND CONSIDERABLE CLOUDS COULD RESULT IN SEP NOT ENDING IN THEWARMEST AND DRIEST SEP ON RECORD. ANOTHER HALF TO ONE INCH OF RAINSEEMS POSSIBLE AT SJU THROUGH THE REMAINDER OF SEP WHICH WOULD PUTTHE RAINFALL TOTALS OVER 1.5 INCHES AND THE RECORD IS 1.49 INCHES. SOWE`LL HAVE TO WAIT AND SEE WHAT HAPPENS.

.UPDATE...SCATTERED SHOWERS HAVE BEEN MOVING OFF OF THE ATLANTICAND ONSHORE IN PUERTO RICO AND THE U.S. VIRGIN ISLANDS AND EXPECTTREND TO CONTINUE THROUGH THE NIGHT. MIMIC PRODUCT SHOWS GOODMOISTURE UPSTREAM FOR AT LEAST THE NEXT 24 TO 36 HOURS. SINCECURRENT FORECAST WAS ANTICIPATING THIS HAVE MADE NO CHANGES TO POPGRIDS.

&&

.DISCUSSION...MOISTURE FROM NORTH AND SOUTH CONTINUE TO MERGE OVERTHE AREA AS WEAK UPPER LOW MOVES WESTWARD JUST SOUTH OF HAITI ANDSECOND UPPER LOW IS VISIBLE ABOUT 750 MILES EAST NORTHEAST OF SANJUAN. ONLY CHANGES TO FORECAST INVOLVE INCREASING HIGHS ON THENORTH HALF OF PUERTO RICO DUE TO SOUTHERLY FLOW NOTED FRIDAYTHROUGH MONDAY. CLOUDS ON SATURDAY WILL LIKELY KEEP TEMPERATURES ONSATURDAY BELOW 90 DEGREES FOR THE SAN JUAN METRO AREA. OTHERWISEEXPECT ABOVE NORMAL TEMPERATURES.

&&

.AVIATION...VFR CONDS ARE EXPECTED TO PREVAIL ACROSS ALL TAF SITESOVERNIGHT. HOWEVER...SCT -SHRA EMBEDDED IN THE LLVL NELY FLOW MAYAFFECT TIST...TISX AND TJSJ FROM TIME TO TIME. 26/00Z TJSJ RAOBSHOWED MAINLY NE WINDS AT 15 KTS OR LESS BLW 25 KFT.

* AT 405 PM AST...DOPPLER RADAR INDICATED SHOWERS AND THUNDERSTORMSWITH VERY HEAVY RAIN IN THE ADVISORY AREA. THIS HEAVY RAIN WILLCONTINUE TO AFFECT THE ADVISORY AREA DURING THE NEXT HOUR OR SO.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE ELEVATED LEVELS ONSMALL CREEKS AND STREAMS...AND PONDING OF WATER IN URBANAREAS...HIGHWAYS...STREETS AND UNDERPASSES AS WELL AS OTHER POORDRAINAGE AREAS AND LOW LYING SPOTS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN. MOVE TOHIGHER GROUND.

* AT 405 PM AST...DOPPLER RADAR INDICATED SHOWERS AND THUNDERSTORMSWITH VERY HEAVY RAIN IN THE ADVISORY AREA. THIS HEAVY RAIN WILLCONTINUE TO AFFECT THE ADVISORY AREA DURING THE NEXT HOUR OR SO.

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE ELEVATED LEVELS ONSMALL CREEKS AND STREAMS...AND PONDING OF WATER IN URBANAREAS...HIGHWAYS...STREETS AND UNDERPASSES AS WELL AS OTHER POORDRAINAGE AREAS AND LOW LYING SPOTS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN. MOVE TOHIGHER GROUND.

.SYNOPSIS...LOW EMBEDDED IN THE NORTHEAST TO SOUTHWEST ORIENTEDTUTT WILL CONTINUE TO RETROGRESS TOWARD HISPANIOLA TONIGHT...WITHMID TO UPPER LEVEL RIDGE THEN BUILDING ACROSS THE LOCAL AREADURING THE NEXT COUPLE OF DAYS.

&&

.DISCUSSION...UPPER LEVEL LOW WILL CONTINUE TO RETROGRESS TOWARDHISPANIOLA TONIGHT...WITH CONTINUED MOISTURE ADVECTION ANDFAVORABLE UPPER LEVEL DYNAMICS ALLOWING AFTERNOON SHOWERS ANDTHUNDERSTORMS ACROSS PARTS OF THE LOCAL AREA TO LINGER THROUGH ATLEAST EARLY THIS EVENING. MID TO UPPER LEVEL RIDGE IS THENEXPECTED TO BUILD ACROSS THE LOCAL AREA...BUT AVAILABLE MOISTUREAND DIURNAL HEATING WILL STILL COMBINE TO PRODUCE AFTERNOONSHOWERS AND THUNDERSTORMS ACROSS CENTRAL AND SOUTHWEST PUERTO RICOWEDNESDAY AND THURSDAY SHIFTING TOWARD CENTRAL AND WEST PUERTORICO ON FRIDAY. THEREAFTER...APPROACHING MID TO MOSTLY UPPERTROUGH AND ASSOCIATED...SLOWLY DEEPENING SURFACE LOW PRESSUREACROSS THE CENTRAL CARIBBEAN...WILL EVENTUALLY CREATE A MORESOUTHERLY FLOW...BRINGING SOME MOISTURE FROM SOUTH AMERICA INTOTHE LOCAL AREA DURING THE WEEKEND.

&&

.AVIATION...AFTERNOON THUNDERSTORMS ACROSS THE INTERIOR ANDWESTERN SECTIONS OF PUERTO RICO WILL AFFECT THE AREAS AROUND TJMZAND POSSIBLY TJPS...THEREAFTER...VFR CONDITIONS WILL PREVAILACROSS ALL TAF SITES THIS EVENING AND OVERNIGHT. WINDS WILL BECOMELIGHT AND VARIABLE TONIGHT AT THE SURFACE AND FROM THE EASTNORTHEAST AT AROUND 10 KTS AT 2K FT. SHRA/TSRA ARE ONCE AGAINEXPECTED TOMORROW AFTERNOON ACROSS THE INTERIOR...SOUTHERN...ANDWESTERN PR.

&&

.MARINE...GENERALLY EXPECT WINDS OF 17 KNOTS OR LESS AND SEAS OF6 FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH AT LEASTTHURSDAY. PULSES OF NORTHEAST SWELLS WILL CONTINUE TO AFFECTTHE ATLANTIC COASTAL WATERS AND THE CARIBBEAN PASSAGES FOR THENEXT FEW DAYS. SMALL BOAT OPERATORS SHOULD CONTINUE TO EXERCISECAUTION ACROSS PARTS OF THE REGIONAL WATERS TONIGHT.

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR MINOR FLOODING OF POOR DRAINAGE AREAS IN FOR THE FOLLOWING MUNICIPALITIES...

IN PUERTO RICO ANASCO...LAS MARIAS...RINCON AND MAYAGUEZ

* UNTIL 445 PM AST

* AT 149 PM AST...DOPPLER RADAR ESTIMATED VERY HEAVY RAIN IN THEADVISORY AREA. THE HEAVY RAINS WILL CONTINUE TO SLOWLY MOVE WESTWARDFOR THE NEXT COUPLE OF HOURS. THIS WILL LEAD TO QUICK RISES IN SMALLRIVERS AND STREAMS AS WELL AS MINOR FLOODING OF POOR DRAINAGE AREAS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

.SYNOPSIS...UPPER LEVEL RIDGE WILL BUILD OVER THE AREA AS UPPERLEVEL LOW IN A NORTHEAST-SOUTHWEST TROUGH CONTINUES TO RETROGRESSTOWARD THE HISPANIOLA.

&&

.DISCUSSION...UPPER LEVEL LOW IN A NORTHEAST-SOUTHWEST TROUGH WILLCONTINUE TO RETROGRESS TOWARD THE HISPANIOLA. THIS WILL RESULT INMOISTURE ADVECTION AND FAVORABLE UPPER LEVEL DYNAMICS THROUGHOUTTHE DAY...WITH SHOWERS AND THUNDERSTORMS ACROSS PORTIONS OF THELOCAL AREA. THE HEAVIEST SHOWERS AND THUNDERSTORMS ARE ANTICIPATEDACROSS CENTRAL AND SOUTHWEST PUERTO RICO LATER TODAY AND MAY INDUCEURBAN FLOODING. UPPER LEVEL RIDGE IS THEN EXPECTED TO BUILD ACROSSTHE LOCAL AREA...BUT AVAILABLE MOISTURE AND DIURNAL HEATING WILLCOMBINE TO PRODUCE AFTERNOON SHOWERS AND THUNDERSTORMS ACROSSCENTRAL AND SOUTHWEST PUERTO RICO WEDNESDAY AND THURSDAY SHIFTINGTOWARD CENTRAL AND WEST PUERTO RICO ON FRIDAY. THERE WILL BE ADRYING TREND THURSDAY AND FRIDAY...HOWEVER SURFACE LOW PRESSUREACROSS THE CENTRAL CARIBBEAN IS EXPECTED TO DEEPEN. THIS WILLCREATE A MORE SOUTHERLY FLOW...BRINGING UP SOME MOISTURE FROMSOUTH AMERICA OVER THE WEEKEND.

&&

.AVIATION...SCT-NMRS SHRA AND ISOLD TSRA TODAY WITH PREDOMINANT CIGSBKN040 DROPPING BELOW 3KFT IN TSRA ESPECIALLY AT JMZ. WINDS FROM THEENE AT 15G21KT XCPT FOR A NW WIND AROUND 10KT AT JMZ.

&&

.MARINE...SEAS HOLD NEAR 5 TO 6 FEET IN OPEN WATERS THROUGH WEDNESDAYAND FALL AS WINDS DIMINISH. PULSES OF NORTHEAST SWELLS WILL AFFECTTHE ATLANTIC COASTAL WATERS AND THE CARIBBEAN PASSAGES FOR THENEXT FEW DAYS.

&&

.CLIMATE...AT THE SAN JUAN AREA...SEPTEMBER 2012 CURRENTLY RANKS ASTHE DRIEST SEPTEMBER ON RECORD WITH ONLY 0.81 INCHES SO FAR. INTERMS OF TEMPERATURES...SEPTEMBER 2012 REMAINS ON PACE TO BE ONEOF THE WARMEST SEPTEMBER ON RECORD. THE AVERAGE TEMPERATURE SO FARHAS BEEN 85.1 DEGREES. THE WARMEST SEPTEMBER ON RECORD WASSEPTEMBER 1995 WITH AN AVERAGE TEMPERATURE OF 84.9 DEGREES. INADDITION...SEPTEMBER 2012 CURRENTLY RANKS AS THE THIRD HOTTESTMONTH OF ANY YEAR...TYING JUNE AND JULY 1980. THE HOTTEST MONTHEVER WAS JUNE 2012 WITH AN AVERAGE TEMPERATURE OF 85.7 DEGREES.

AT CYRIL E. KING AIRPORT/SAINT THOMAS...SEPTEMBER 2012 CURRENTLYRANKS AS THE DRIEST SEPTEMBER ON RECORD WITH 0.81 INCHES SO FAR.

.SYNOPSIS...AT UPPER LEVELS...A LOW IN A NORTHEAST-SOUTHWESTTROUGH SITS OVER EASTERN PUERTO RICO AND WILL MOVE ACROSSHISPANIOLA DURING THE NEXT FEW DAYS. AFTER WEDNESDAY...HIGHPRESSURE BUILDS OVER THE AREA AND THE LOW PRESSURE TO THENORTHEAST RETREATS AND DISSIPATES.

AT MID LEVELS...A WEAK TROUGH OVER THE LEEWARD ISLANDS MOVESTHROUGH THE LOCAL AREA ON TUESDAY FOLLOWED BY WEAK TROUGHINESSOVER THE AREA THROUGH FRIDAY. THEN HIGH PRESSURE VERY SLOWLY BUILDSFROM THE EAST SATURDAY THROUGH THE FOLLOWING TUESDAY.

AT LOWER LEVELS...HIGH PRESSURE IN THE CENTRAL ATLANTIC AND LOWPRESSURE IN THE SOUTHWEST CARIBBEAN KEEP MODERATE TO FRESH TRADEWIND FLOW OVER THE LOCAL AREA UNTIL FRIDAY. AS LOW PRESSUREDEEPENS OVER THE WESTERN CARIBBEAN AND EXTENDS INTO THE GULF OFMEXICO FRIDAY NIGHT...HIGH PRESSURE BUILDS INTO THE CENTRALTROPICAL ATLANTIC CREATING MORE SOUTHERLY FLOW THAT BRINGS UP SOMEMOISTURE FROM SOUTH AMERICA OVER THE WEEKEND. HIGH PRESSURERETURNS TO THE WESTERN ATLANTIC LATE NEXT WEEK BRINGING A RESUMPTIONOF THE TRADE WINDS.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS BEGAN FORMING AFTER 1 PMAST AND BY 2:30 PM CELLS WERE SCATTERED IN A CHAIN FROM SAINTTHOMAS TO CEIBA AND FROM OROCOVIS TO CABO ROJO. THE STRONG HEATINGPROMISES TO ALLOW MORE SUCH CELLS TO FORM BEFORE SUNSET ANDCONTINUE TO BRING SHOWERS TO SOUTHWEST PUERTO RICO. TEMPERATURESCONTINUE QUITE WARM WITH 92 DEGREES...SO FAR...IN SAN JUAN. CHANGESIN THE PATTERN WILL BE SMALL AND GRADUAL WITH MOISTURE INCREASINGSLOWLY AND WINDS DECREASING AFTER TOMORROW. ALTHOUGH THERE WILL BEA LITTLE DRYING TREND ON FRIDAY THE PATTERN DESCRIBED ABOVE THATBRINGS MOIST FLOW TO THE AREA FROM SOUTH AMERICA SHOULD GENERATEINCREASING SHOWERS SATURDAY AND SUNDAY. THE NORTH COAST MAYRECEIVE LITTLE OF THIS IF LINES DO NOT FORM TO MOVE NORTH OVER THECOAST...DUE TO THE OROGRAPHIC SHADOWING...BUT THE SOUTH FACINGSLOPES SHOULD RECEIVE NEEDED MOISTURE. AFTER THE WEEKEND MOISTUREDIMINISHES AGAIN AND FLOW RETURNS TO THE EAST SOUTHEAST ONLYMODEST SHOWER ACTIVITY IS EXPECTED.

&&

.AVIATION...AFTERNOON THUNDERSTORMS ACROSS THE INTERIOR AND WESTERN SECTIONSOF PUERTO RICO WILL AFFECT THE AREAS AROUND TJMZ AND POSSIBLYTJPS...THEREAFTER...VFR CONDITIONS WILL PREVAIL ACROSS ALL TAFSITES THIS EVENING AND OVERNIGHT. WINDS WILL BECOME LIGHT ANDVARIABLE TONIGHT AT THE SURFACE AND FROM THE EAST NORTHEAST ATAROUND 10 KTS AT 2K FT. SHRA/TSRA ARE ONCE AGAIN EXPECTED TOMORROWAFTERNOON ACROSS SOUTHERN AND WESTERN PR. EXPECT ISOLD TOPS OF 45TO 55 KFT OVER LAND TILL ARND 24/22Z.

&&

.MARINE...SEAS HOLD NEAR 5 TO 6 FEET IN OPEN WATERS THROUGHWEDNESDAY AND FALL AS WINDS DIMINISH. NADINE IS ALMOST 2500 MILESEAST NORTHEAST AND WILL PROVIDE ABOUT HALF OF THE SWELL TO BE SEENIN THE LOCAL AREA THROUGH NEXT MONDAY.

.SYNOPSIS...TUTT WITH EMBEDDED LOWS EXTENDING FROM THE CENTRALATLANTIC INTO THE EASTERN AND CENTRAL CARIBBEAN WILL REMAIN THEMAIN WEATHER FEATURE LOCALLY FOR THE NEXT FEW DAYS.

&&

.DISCUSSION...UPPER LEVEL LOW LOCATED NEAR PUERTO RICO ANDASSOCIATED WITH AFOREMENTIONED TUTT WILL RETROGRESS TOWARD THEDOMINICAN REPUBLIC BY TUESDAY. AS A RESULT...MOISTURE ADVECTIONAND FAVORABLE UPPER LEVEL DYNAMICS ARE EXPECTED TO INCREASETOMORROW WITH AFTERNOON CONVECTION ACROSS CENTRAL AND SOUTHWESTPUERTO RICO TUESDAY AND WEDNESDAY SHIFTING TOWARDS NORTHWESTPUERTO RICO ON THURSDAY. AS THIS PATTERN EVOLVES...CONTINUE TOEXPECT ISOLATED TO LOCALLY SCATTERED AFTERNOON SHOWERS ANDTHUNDERSTORMS ACROSS CENTRAL AND SOUTHWEST PUERTO RICO TODAY.THESE SHOWERS AND THUNDERSTORMS ARE ANTICIPATED MAINLY DUE TOLOCAL EFFECTS AND DIURNAL HEATING. MODEL GUIDANCE CONTINUES TOSUGGEST A WETTER WEATHER PATTERN FOR THE END OF THE WORK WEEKINTO THE UPCOMING WEEKEND AS A SURFACE LOW DEVELOPS ACROSS THECENTRAL CARIBBEAN.

&&

.AVIATION...AN ISOLD TSRA IN THE VCNTY OF JMZ THIS AFTERNOON.OTHERWISE...VFR CONDITIONS AT ALL OTHER TAF SITES WITH NO SIG WX.ENE SFC WINDS 16G23KT DURING THE DAY BCMG L/V AFTER SUNSET XCPTFOR A WNW WIND AROUND 10 KT AT JMZ IN THE AFTERNOON.

&&

.MARINE...GENERALLY EXPECT WINDS OF 17 KNOTS OR LESS AND SEAS OF6 FEET OR LESS IN NORTHEAST SWELLS ACROSS THE REGIONAL WATERSTHROUGH AT LEAST TUESDAY.

.SYNOPSIS...TUTT WITH EMBEDDED LOWS EXTENDING FROM THE CENTRALATLANTIC INTO THE EASTERN AND CENTRAL CARIBBEAN WILL REMAIN THEMAIN WEATHER FEATURE LOCALLY FOR THE NEXT SEVERAL DAYS.

&&

.DISCUSSION...EXPECT A RELATIVELY DRY AIR MASS FOR TONIGHT ANDMONDAY...BUT LOCAL EFFECTS SHOULD ALLOW FOR SOME LIMITEDCONVECTION AGAIN MONDAY AFTERNOON OVER THE CENTRAL AND WESTERNINTERIOR...WEST AND SOUTHWEST SECTIONS OF PUERTO RICO. AT THE SAMETIME...AFOREMENTIONED TUTT AND ASSOCIATED LOWS WILL CONTINUE TORETROGRADE WESTWARD WITH ITS AXIS REACHING THE LOCAL AREA MONDAYTHROUGH TUESDAY. AS A RESULT...MOISTURE ADVECTION AND FAVORABLEUPPER LEVEL DYNAMICS ARE EXPECTED WITH AN INCREASE IN AFTERNOONCONVECTION ACROSS CENTRAL AND SOUTHWEST PUERTO RICO TUESDAY ANDWEDNESDAY SHIFTING TOWARDS NORTHWEST PUERTO RICO ON THURSDAY.THEREAFTER...MODEL GUIDANCE CONTINUES TO SUGGEST THE POSSIBILITYOF A WET/ACTIVE WEATHER PATTERN FOR THE END OF THE WORK WEEK INTOTHE UPCOMING WEEKEND...AS A BROAD SURFACE TROUGH DEVELOPS ACROSSTHE CENTRAL CARIBBEAN. STAY TUNED.

&&

.AVIATION...MOSTLY VFR CONDITIONS WILL PREVAIL ACROSS ALL TAFSITES THIS EVENING AND OVERNIGHT. FOR MONDAY AFTERNOON CONVECTIONWILL DEVELOP ACROSS CENTRAL...NORTH AND WEST PR FROM24/16Z-24/22Z. AS A RESULT...BRIEF MVFR CONDITIONS WILL OCCUR NEAROR OVER TJMZ AND TJBQ...WITH MOUNTAIN TOP OBSCURATIONS OVERINTERIOR PR. LATEST 23/12Z TJSJ SOUNDING INDICATED MAINLY EAST TOSOUTHEAST WINDS FROM THE SURFACE UP TO 20K FEET...BECOMINGNORTHEASTERLY ABOVE.

&&

.MARINE...GENERALLY EXPECT WINDS OF 18 KNOTS OR LESS AND SEAS OF6 FEET OR LESS IN NORTHEAST SWELLS ACROSS THE REGIONAL WATERSTHROUGH AT LEAST TUESDAY.

.SYNOPSIS...TUTT EXTENDING FROM THE CENTRAL ATLANTIC INTO THEEASTERN CARIBBEAN...WITH ASSOCIATED LOWS THE FIRST AND DEEPERNEAR 30N/60W AND THE SECOND LOW OVER THE LEEWARD ISLANDS...WILLCONTINUE TO DOMINATE THE LOCAL WEATHER PATTERN FOR THE NEXT FEWDAYS.

&&

.DISCUSSION...AFOREMENTIONED TUTT AND ASSOCIATED LOWS WILL CONTINUETO RETROGRADE WESTWARD WITH ITS AXIS REACHING THE LOCAL AREA MONDAYTHROUGH TUESDAY. AS A RESULT...MOISTURE ADVECTION AND FAVORABLEUPPER LEVEL DYNAMICS ARE EXPECTED EARLY NEXT WORK WEEK WITH ANINCREASE IN AFTERNOON CONVECTION ACROSS CENTRAL AND SOUTHWEST PUERTORICO TUESDAY AND WEDNESDAY SHIFTING TOWARDS NORTHWEST PUERTO RICOON THURSDAY. MEANWHILE...AIR MASS DRIES OUT SIGNIFICANTLY TODAY ANDMONDAY...BUT LOCAL EFFECTS AND DIURNAL HEATING WILL INDUCE SPOTTYCONVECTION ACROSS CENTRAL AND WEST PUERTO RICO BOTH DAYS. MODELGUIDANCE CONTINUES TO SUGGEST A WET/ACTIVE WEATHER PATTERN FOR THEEND OF THE WORK WEEK INTO THE UPCOMING WEEKEND AS A BROAD SURFACETROUGH DEVELOPS ACROSS THE CENTRAL CARIBBEAN.

&&

.AVIATION...AN ISOLD TSRA POSSIBLE AT JBQ AND JMZ THIS AFTERNOONBUT PROB TOO LOW TO HAVE EITHER A VCTS OR PROB30 GROUP.OTHERWISE...VFR CONDITIONS AT ALL OTHER TAF SITES WITH NO SIG WX.ONSHORE SFC WINDS 15G20KT DURING THE DAY BCMG L/V AFTER SUNSET.

&&

.MARINE...PULSES OF NORTHEAST SWELLS WILL AFFECT THE ATLANTICCOASTAL WATERS THROUGH MID NEXT WEEK. HOWEVER...TRANQUIL MARINECONDITIONS EXPECTED TO PREVAIL TODAY WITH SEAS UP TO 5 FEET ANDWINDS OF 17 KNOTS OR LESS.

.UPDATE...SKIES BECAME MOSTLY CLEAR TO PARTLY CLOUDY OVER THEISLANDS AND COASTAL WATERS WITH NO SHOWER ACTIVITY NOTED OVERLAND. FEW SHOWERS AND ISOLATED THUNDERSTORMS HOWEVER CONTINUEDACROSS THE OFFSHORE CARIBBEAN AND ATLANTIC WATERS WITH A GENERALMOTION TO THE WEST NORTHWEST. LATEST WATER VAPOR IMAGERY ANDLATEST GFS MODEL GUIDANCE INITIALIZED FAIRLY WELL AND DEPICTEDUPPER LOW/TUTT NOW ACROSS THE SOUTHEAST CARIBBEAN AND CONTINUEDTO RETROGRESS WESTWARD WHILE FILLING.

OVERALL LATEST TJSJ 23/00Z UPPER AIR SOUNDING AS WELL AS THAT OFMACM (ST MARTEEN)...TFFR (GUADELOUPE) AND BLENDED TPW ALL SUGGESTA SOMEWHAT DRIER AIR MASS MOVING ACROSS THE REGION. HOWEVER...STILLEXPECT SUFFICIENTLY HUMID CONDITIONS FOR DIURNALLY INDUCED AFTERNOONCONVECTION ONCE AGAIN ON SUNDAY. INHERITED FORECAST PACKAGE ALREADYREFLECTED THE EXPECTED WEATHER CONDITIONS AND THEREFORE NO CHANGESWERE MADE TO THE INHERITED FORECAST GRIDS FOR NOW PENDING NEW MODELGUIDANCE AND DATA.

&&

.AVIATION UPDATE...MOSTLY VFR CONDS WILL PREVAIL ACROSS ALL TAFSITES THROUGH AT LEAST 23/16Z. AFTERNOON CONVECTION WILL DEVELOPACROSS CENTRAL...NORTH AND WEST PR FROM 23/16Z-23/22Z. AS ARESULT...BRIEF MVFR CONDS WILL OCCUR VCNTY OR OVR TJMZ ANDTJBQ...WITH MTN TOP OBSCURATIONS OVER INTERIOR PR. LATEST 23/00ZTJSJ SOUNDING INDICATED MAINLY EAST TO SOUTHEAST WINDS FROM THESFC-100 KFT...BECOMING NORTHEASTERLY ABOVE.

.SYNOPSIS...COMPUTER MODEL GUIDANCE AS WELL AS SATELLITE ANALYSISDEPICTED TWO TUTT LOWS...ONE ACROSS THE CENTRAL ATLANTIC JUST NORTHNORTHEAST OF THE FA AND ANOTHER ONE JUST ACROSS THE LESSER ANTILLES.THE UPPER LOW ACROSS THE CENTRAL ATLANTIC IS EXPECTED TO RETROGRADESLOWLY SOUTH SOUTHWESTWARD APPROACHING TO THE LOCAL ISLANDS DURINGTHE NEXT FEW DAYS WHILE FILLING. THE UPPER LOW ACROSS THE LESSER ANTILLESIS EXPECTED TO MOVE SLOWLY WESTWARD WHILE FILLING...OVER THE CENTRALCARIBBEAN THESE FEATURES WILL MAINTAIN A RELATIVELY UNSTABLEWEATHER PATTERN ACROSS THE REGION UNTIL AT LEAST THE MIDDLE OF THEUPCOMING WEEK.

&&

.DISCUSSION...MOSTLY CLEAR SKIES PREVAILED DURING THE LATE MORNINGHOURS ACROSS THE LOCAL REGION. ONLY FEW ISOLATED TO SCATTEREDSHOWERS WERE DETECTED MAINLY ACROSS THE SURROUNDING COASTAL WATERS.HOWEVER...SHOWERS AND THUNDERSTORMS DEVELOPED ACROSS NORTH CENTRALSECTIONS OF PUERTO RICO EARLY IN THE AFTERNOON...MOVING LATER OVERNORTHWESTERN SECTIONS OF PUERTO RICO. THIS ACTIVITY WILL CONTINUEUNTIL LATE AFTERNOON OR EARLY EVENING HOURS. COMPUTER MODEL GUIDANCEAND SATELLITE IMAGERY THIS AFTERNOON...DEPICTED SEVERAL LOW LEVELPERTURBATIONS/REFLECTIONS ASSOCIATED WITH THE AFOREMENTIONED UPPERLEVEL LOWS. THESE PERTURBATIONS WILL MOVE ACROSS THE LOCAL ISLANDSFROM TIME TO TIME DURING THE NEXT SEVERAL DAYS...PRODUCING INTERVALSOF CLOUDINESS...SHOWERS AND THUNDERSTORMS...ACROSS EASTERN SECTIONSOF PUERTO RICO DURING THE NIGHTS AND ACROSS WESTERN...NORTHWEST ANDINTERIOR SECTIONS OF PUERTO RICO DURING THE AFTERNOONS. PWAT VALUESWILL REMAIN IN THE RANGE 1.50-2.00 INCHES FOR THE FORECAST PERIODS.THESE PWAT VALUES DO NOT SUPPORT WIDESPREAD SHOWERS ANDTHUNDERSTORMS...BUT THE COMBINATION OF STRONG DIURNAL HEATING...LOCAL OROGRAPHIC EFFECTS AND MARGINAL FAVORABLE UPPER LEVEL DYNAMICIS EXPECTED TO INDUCE FEW AREAS OF HEAVY SHOWERS ANDTHUNDERSTORMS...SPECIALLY ACROSS NORTHERN AND NORTHWEST SECTIONS OFPUERTO RICO EACH AFTERNOON. THE GFS MODEL GUIDANCE SUGGESTS ANINCREASE IN MOISTURE TONIGHT AND EARLY SUNDAY AS ANOTHER LOW LEVELREFLECTION/PERTURBATION MOVES ACROSS THE REGION. THIS TYPE OFWEATHER PATTERN WILL PREVAIL ACROSS THE FA UNTIL THE MIDDLE OF THEUPCOMING WEEK.

BY THE NEXT WEEKEND...MODELS INDICATED THAT A SURFACE LOW PRESSURECENTER WILL DEVELOP SOUTH OF THE REGION...INDUCING A VERY DEEP MOISTAND UNSTABLE SOUTHEAST WIND FLOW AND GENERAL INCREASE IN MOISTUREACROSS THE FA. STAY TUNED.

&&

.AVIATION...VFR CONDITIONS WILL CONTINUE AT ALL TAF SITES WITHISOLATED PASSING SHOWERS POSSIBLE IN AND AROUND TIST/TISX...TNCM/TKPK AND TJSJ OVERNIGHT AND EARLY IN THE MORNING. AFTER23/17Z...SHRA/TSRA EXPECTED TO DEVELOP...AFFECTING MAINLY TJBQ ANDTHE VICINITY OF TJMZ AND TJSJ. AS A RESULT...BRIEF MVFR CONDITIONSAND MOUNTAIN OBSCURATIONS WILL OCCUR. WINDS FROM SURFACE TO 15KFTWILL BE MAINLY FROM THE SOUTHEAST BETWEEN 5-10 KTS.

SHOWERS AND THUNDERSTORMS OVER THE ADVISORY AREA ARE PRODUCINGMODERATE TO HEAVY RAIN. THESE STORMS WILL SLOWLY MOVE WESTWARDDURING THE NEXT COUPLE HOURS...HOWEVER ADDITIONAL SHOWERS WILLLIKELY MOVE INTO THE AREA DURING THE REST OF THIS AFTERNOON. THEHEAVIEST SHOWERS WILL PRODUCE MINOR NUISANCE FLOODING ON ROADWAYS ININ POOR DRAINAGE AREAS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

.SYNOPSIS...TUTT TROUGH EXTENDING FROM AROUND 30N60W WITH LOWCOUPLETS THE FIRST AND DEEPER LOW NEAR 30N/60W THE SECOND LOW OVERTHE SOUTHERN LEEWARD ISLANDS. TUTT TROUGH AND ASSOCIATED LOWS WILLCONTINUE TO FILL AND RETROGRADE WESTWARD WITH A SOUTHWEST TONORTHWEST AXIS OF THE TUTT ACROSS THE LOCAL AREA MONDAY THROUGHTUESDAY.

.DISCUSSION...MIXED BAG OF FORECAST PARAMETERS TODAY...WE AREDRIER THAT WE HAVE BEEN THE PAST COUPLE OF DAYS WITH PRECIPITABLEWATER DROPPING TO 1.6 INCHES...LESS LOW LEVEL SHEAR...WITHHELICITY VALUES OF 1 TODAY COMPARED TO A -3 YESTERDAY. YOU WOULDTHINK THAT LOWER MOISTURE AND LESS SHEAR WOULD LEAVE A DRIERFORECAST...I GUESS AREA WISE THAT WOULD BE CORRECT. THE ONLY FLYIN THE OINTMENT IS THAT I BELIEVE WE ARE STARTING TO SEE THEINTRUSION OF SOME COOLER AIR ALOFT. FREEZING LEVEL HAS DROPPEDABOUT 600 FEET SINCE YESTERDAY AT THIS TIME...ADD TO THAT AN SMALLINCREASE IN VERTICAL VELOCITIES...MORE CAPE TO PLAY WITH (3924J/KG) AND A NICE LIFTING INDEX OF -7.0. WHAT THIS MEANS IS THATALTHOUGH WE HAVE LESS MOISTURE...THE SHOWER/THUNDERSTORM THAT DODEVELOP WILL HAVE A BIT MORE LIFT AND ENERGY SO WHERE THEY OCCURLOOK FOR SOME VERY HEAVY DOWNPOURS...AND MAYBE A VERY SLIGHTCHANCE OF A VERY ISOLATED BOOMER PRODUCING SMALL HAIL...MOSTLYLIKELY SOMEWHERE ACROSS THE NORTHWEST COURNER OF MAINLAND PUERTORICO. OTHERWISE...SHOWERS AND THUNDERSTORMS WILL LIMIT TOSTREAMERS THAT DEVELOP ON THE LESS SIDE OF THE U.S.V.I.CULEBRA...VIEQUES AND EL YUNQUE.

&&

.AVIATION...VFR CONDITIONS WILL CONTINUE AT ALL TAF SITES WITH ISOLATEDPASSING SHOWERS POSSIBLE IN AND AROUND TIST/TISX...TNCM/TKPK AND TJSJTHROUGH THE MORNING HOURS. AFTER 22/17Z...SHRA/TSRA EXPECTED TODEVELOP...AFFECTING MAINLY TJBQ AND THE VICINITY OF TJMZ ANDTJSJ. AS A RESULT...BRIEF MVFR CONDITIONS AND MOUNTAINOBSCURATIONS WILL OCCUR. WINDS FROM SURFACE TO 15KFT WILL BEMAINLY FROM THE SOUTHEAST BETWEEN 5-10 KTS.

.SYNOPSIS...TUTT ACROSS THE ERN CARIB IS EXPECTED TO FILL OVER THENEXT FEW DAYS AS IT RETROGRESSES TOWARD HISPANIOLA. CUTOFF LOWACROSS THE CNTRL ATLC IS FCST TO DROP ALONG 60W AND EXTEND A TROUGHINTO OUR AREA TUE. MID-UPPER LEVEL RIDGING WILL BUILD FOR NEXTWEEKEND.

&&

.DISCUSSION...IT APPEARS THAT WE`LL HAVE ONE MORE ACTIVEAFTERNOON AS INVERTED MID-LEVEL TROF MOVES ACROSS THE AREA LATERTODAY. LATEST GFS AND SREF GUIDANCE SUGGEST THIS ALTHOUGH LOCALWRF AND HI-RES ARW AND NMM SHOW SIG LESS CVRG FOR TODAY WHENCOMPARED TO YDAY. WHILE NO REPORTS OF SVR WX WERE RECEIVED YDAY ISTILL CAN`T RULED OUT SOME HAIL DUE TO FCST OF LOWER -20C HEIGHTAND WBZ LEVELS AND PRETTY UNSTABLE ATMOSPHERE. TUTT FILLS SUN ANDAIR MASS DRIES OUT SIGNIFICANTLY SUN AND MON WITH ONLY SPOTTYCONVECTION.

SECOND CUTOFF LOW ACROSS THE CNTRL ATLC DROPS ALONG 60W ON TUEKEEPING UPPER TROUGHFINESS OVR OUR AREA WITH CYCLONIC VORTICITYAND MOISTURE ADVECTION FOR AN INCREASE IN AFTERNOON CONVECTIONTUE. MORE OF THE SAME WED AND THU WITH CUTOFF LOW WEAKENING WITHTIME AS MID-UPPER LEVEL RIDGE BUILDS FROM THE WEST BY NEXT FRI.

AS ALL OF THIS OCCURS...MODELS SHOW HIGH AMPLITUDE BLOCKINGPATTERN ACROSS THE ATLC BREAKING DOWN WITH A SRN STREAM TROUGHDIGGING ACROSS THE WRN CARIBBEAN AND THEN INTERACTING WITH A BROADSFC LOW OVR THE SW CARIBBEAN. THE NET RESULT IS THE DEVELOPMENT OF ANINVERTED SFC TROF PATTERN ACROSS THE CNTRL CARIBBEAN WITH DEEPMOISTURE BEING PULLED NORTHWARD INTO THE ERN DOM REP AND PR TOWARDTHE END OF NEXT WEEK. THIS LIKELY TO RESULT IN PERIODS OF HEAVYRAIN NEXT SUN SEP 30.

&&

.AVIATION...VFR CONDITIONS WILL CONTINUE AT ALL TAF SITES WITH ISOLATEDPASSING SHOWERS POSSIBLE IN AND AROUND TIST/TISX...TNCM/TKPK AND TJSJTHROUGH THE MORNING HOURS. AFTER 22/17Z...SHRA/TSRA EXPECTED TO DEVELOPACROSS PORTIONS OF PUERTO RICO...AFFECTING MAINLY TJBQ AND THE VICINITYOF TJMZ AND TJSJ. AS A RESULT...BRIEF MVFR CONDITIONS AND MOUNTAINOBSCURATIONS WILL OCCUR. WINDS FROM SURFACE TO 15KFT WILL BE MAINLYFROM THE SOUTHEAST BETWEEN 5-10 KTS.

.CLIMATE...AT THE SAN JUAN AREA...SEPTEMBER 2012 CURRENTLY RANKS ASTHE DRIEST SEPTEMBER ON RECORD WITH ONLY 0.31 INCHES SO FAR. IN TERMSOF TEMPERATURES...SEPTEMBER 2012 REMAINS ON PACE TO BE THE WARMESTSEPTEMBER ON RECORD. THE AVERAGE TEMPERATURE SO FAR HAS BEEN 85.1DEGREES. THE WARMEST SEPTEMBER ON RECORD WAS SEPTEMBER 1995 WITH ANAVERAGE TEMPERATURE OF 84.9 DEGREES. IN ADDITION...SEPTEMBER 2012CURRENTLY RANKS AS THE THIRD HOTTEST MONTH OF ANY YEAR...TYINGJUNE AND JULY 1980. THE HOTTEST MONTH EVER WAS JUNE 2012 WITH ANAVERAGE TEMPERATURE OF 85.7 DEGREES.

AT CYRIL E. KING AIRPORT/SAINT THOMAS...SEPTEMBER 2012 CURRENTLYRANKS AS THE DRIEST SEPTEMBER ON RECORD WITH 0.76 INCHES SO FAR.

.SYNOPSIS...COMPUTER MODEL GUIDANCE AS WELL AS SATELLITE ANALYSISDEPICTED TWO UPPER LEVEL LOWS...ONE ACROSS THE CENTRAL ATLANTIC ANDANOTHER ONE ACROSS THE LESSER ANTILLES. THE UPPER LOW ACROSS THECENTRAL ATLANTIC IS EXPECTED TO MOVE SLOWLY SOUTHWESTWARDAPPROACHING TO THE LOCAL ISLANDS FOR THE NEXT SEVERAL DAYS. THEUPPER LOW ACROSS THE LESSER ANTILLES IS EXPECTED TO MOVE SLOWLYWESTWARD ACROSS THE CENTRAL CARIBBEAN. THESE FEATURES WILL MAINTAINA RELATIVELY UNSTABLE WEATHER PATTERN ACROSS THE REGION UNTIL THEMIDDLE OF THE UPCOMING WEEK.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS DEVELOPED ACROSS CENTRAL ANDINTERIOR SECTIONS OF PUERTO RICO EARLY IN THE AFTERNOON...MOVINGLATER OVER NORTH CENTRAL...NORTHERN AND WESTERN SECTIONS OF PUERTORICO. THIS ACTIVITY WILL CONTINUE UNTIL LATE AFTERNOON OR EARLYEVENING HOURS. SATELLITE IMAGERY THIS AFTERNOON DEPICTED SEVERALLOW LEVEL PERTURBATIONS/REFLECTIONS ASSOCIATED WITH THEAFOREMENTIONED UPPER LEVEL LOWS. THESE PERTURBATIONS WILL MOVEACROSS THE LOCAL ISLANDS FROM TIME TO TIME DURING THE NEXTSEVERAL DAYS...PRODUCING INTERVALS OF CLOUDINESS...SHOWERS ANDTHUNDERSTORMS...ACROSS EASTERN AND NORTHERN SECTIONS OF PUERTORICO DURING THE NIGHTS AND ACROSS WESTERN...NORTHWEST ANDINTERIOR SECTIONS OF PUERTO RICO DURING THE AFTERNOONS. THIS TYPEOF WEATHER PATTERN WILL PREVAIL ACROSS THE FA UNTIL THE MIDDLE OFTHE UPCOMING WEEK.

&&

.AVIATION...MOSTLY VFR CONDS WILL PREVAIL ACROSS ALL TAF SITESTHROUGH THE FORECAST PERIOD. AFTERNOON CONVECTION WILL CONTINUETO DEVELOP ACROSS CENTRAL..NORTH AND WEST PR THROUGH 21/22Z. AS ARESULT...BRIEF MVFR CONDS ARE STILL POSSIBLE NEAR TJMZ AND TJBQ...WITH MTN TOP OBSCR OVR INTERIOR PR. WINDS FM SFC TO 15KFT WILL BEMAINLY FM THE E-SE BTW 5-15 KTS.

* AT 239 PM AST...DOPPLER WEATHER RADAR INDICATED SCATTERED SHOWERSAND ISOLATED STRONG THUNDERSTORMS WITH VERY HEAVY RAIN DEVELOPINGAND MOVING SLOWLY ACROSS THE ADVISORY AREA. THE STORMS WILL MOVEWESTWARD AT 10 MPH...AND WILL AFFECT NEARBY MUNICIPALITIES IN THENEXT FEW HOURS. ADDITIONAL RAINFALL AMOUNTS OF 1 TO 2 INCHES AREPOSSIBLE IN THE ADVISORY AREA THROUGH 545 PM AST.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN. MOVE TOHIGHER GROUND.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN. MOVE TOHIGHER GROUND.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THEROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSSSAFELY. WHEN ENCOUNTERING FLOODED ROADS MAKE THE SMART CHOICE...TURNAROUND...DONT DROWN. MOVE TO HIGHER GROUND.

.SYNOPSIS...A PAIR OF CUTOFF LOWS ONE ACROSS THE CNTRL ATLC ANDANOTHER ONE OVER THE WINDWARD ISLANDS WILL RETROGRESS OVR THE NEXTSVRL DAYS WHILE FILLING/WEAKENING. ANOTHER CUTOFF LOW ACROSS THENE ATLC WILL DROP SOUTHWEST AND EXTEND A TROUGH INTO OUR AREA MIDNEXT WEEK. RIDGE THEN EVENTUALLY BUILDS OVR THE AREA AT THE END OFNEXT WEEK.

&&

.DISCUSSION...PRETTY UNSTABLE ATMOSPHERE THIS MORNING PERNUMEROUS SHOWERS ON RADAR IMAGERY AND COLD CLOUD TOPS TO -50C ONIR IMAGERY. THIS INSTABILITY AXIS CURRENTLY LOCATED ACROSS THECARIB WILL RETROGRESS IN TANDEM WITH TUTT LOW LOCATED NEARMARTINIQUE TO GIVE US AN ACTIVE DAY. DUE TO LOWERING WET-BULB ZEROLEVELS AND LOWERING OF THE -20C HEIGHT SOME HAIL COULD OCCUR WITHTHE STRONGEST CELLS. THERE IS BETTER MOISTURE ON SAT FOR BETTERTSTM CVRG THAN TODAY WITH TSTM ACTIVITY FCST TO CONCENTRATE ACROSSNCNTRL/NWRN PR. TUTT WEAKENS SIGNIFICANTLY BY SUN WITH MODELSSHOWING SIG MID LEVEL DRYING BUT H5 COOL POOL WITH TEMPS AROUND-8C WILL BE OVERHEAD. SO WHILE THERE SHOULD BE LESS CVRG...TSTMSCOULD BE MORE VIGOROUS AND AGAIN CONTAIN SOME HAIL.

TUTT FILLS/WEAKENS BY EARLY NEXT WEEK BUT ENOUGH MOISTURE WILL BEAROUND EACH DAY TO GIVE US SCT DIURNAL ACTIVITY. BY THE END OFNEXT WEEK...MODELS SHOW HIGH AMPLITUDE BLOCKING PATTERN ACROSS THEATLC BREAKING DOWN WITH A SRN STREAM TROUGH ACROSS FL/BAHAMAS ANDCNTRL CARIBBEAN INTERACTING WITH EPAC/SW CARIBBEAN MONSOON TROFWITH DEEP MOISTURE FCST TO POOL ACROSS HISPANIONA...PR AND EASTCNTRL CARIBBEAN SEA. SO CONDITIONS RIGHT TOWARD THE END OF THEMONTH/START OF OCT COULD TURN VERY WET.

&&

.AVIATION...VFR CONDITIONS WILL CONTINUE AT ALL TAF SITES WITHISOLATED PASSING SHOWERS POSSIBLE IN AND AROUND TIST/TISX...TNCM/TKPK AND TJSJ THROUGH THE MORNING HOURS. AFTER 21/16Z...SHRA/TSRA EXPECTED TO DEVELOP ACROSS PORTIONS OF PUERTO RICO...AFFECTING MAINLY TJBQ AND THE VICINITY OF TJMZ AND TJSJ.

.CLIMATE...SEPTEMBER 2012 AT THE SAN JUAN AREA REMAINS AS THE DRIESTSEPTEMBER ON RECORD TO DATE WITH ONLY 0.31 INCHES SO FAR. IN TERMS OFTEMPERATURE...SEPTEMBER 2012 REMAINS ON PACE TO BE THE WARMESTSEPTEMBER ON RECORD. THE AVERAGE TEMPERATURE SO FAR HAS BEEN 85.1DEGREES. THE WARMEST SEPTEMBER ON RECORD WAS SEPTEMBER 1995 WITHAN AVERAGE TEMPERATURE OF 84.9 DEGREES. AT CYRIL E. KINGAIRPORT/SAINT THOMAS AND CHRISTIANSTED AIRPORT/SAINTCROIX...SEPTEMBER 2012 REMAINS AS THE DRIEST AND SECOND DRIESTSEPTEMBER ON RECORD WITH 0.76 AND 1.38 INCHES RESPECTIVELY.

.UPDATE...AFTERNOON CONVECTION ACROSS THE WEST INTERIOR ANDSOUTHWEST SECTIONS OF PUERTO RICO QUICKLY DISSIPATED AFTER SUNSETLEAVING PARTLY CLOUDY SKIES...MOST OF WHICH WERE MID TO HIGHLEVEL CLOUDINESS. FEW SHOWERS CONTINUED ACROSS THE COASTAL WATERSWITH SOME BRIEFLY REACHING THE NORTH AND EAST COASTAL SHORES FROMTIME TO TIME. RAINFALL AMOUNTS WERE HOWEVER MINIMAL WITH LITTLEACCUMULATIONS.

LATEST SATELLITE IMAGERY SHOWED ONLY SMALL PATCHES OF SHALLOWMOISTURE MOVING ACROSS THE NORTHEAST CARIBBEAN...WHILE WATER VAPORIMAGERY SUGGESTS GOOD CYCLONIC CIRCULATION WITH TUTT LOW JUST EASTOF THE ISLAND OF MARTINIQUE. EXPECT THIS LOW TO CONTINUE WESTWARDOVERNIGHT AND ENTER THE EASTERN CARIBBEAN ON FRIDAY. IN ADDITION AWEAK TROPICAL WAVE JUST EAST OF THE WINDWARD ISLANDS CONTINUED TOINTERACT WITH THE TUTT LOW AND WILL ALSO ENTER AND MOVE ACROSS THEEASTERN CARIBBEAN OVER THE NEXT FEW DAYS. NO SIGNIFICANT AMOUNTSOF LOW LEVEL MOISTURE ADVECTION AT THIS TIME HOWEVER STILL EXPECTTHE COMBINATION OF THESE TWO APPROACHING FEATURES TO BRING MOREFAVORABLE CONDITIONS FOR SOME ACTIVE WEATHER ESPECIALLY DURING THEAFTERNOON HOURS EACH DAY THROUGH THE UPCOMING WEEKEND AS PREVIOUSLYMENTIONED. NO MAJOR CHANGES MADE TO THE INHERITED FORECAST PACKAGEAT THIS TIME

.SYNOPSIS...UPPER LEVEL RIDGE WILL SHIFT WEST AS UPPER LEVELTROUGH INVADE OUR LOCAL REGION FROM THE EAST. THIS WEATHER PATTERNWILL PERSIST THROUGH AT LEAST MID NEXT WEEK.

&&

.DISCUSSION...SHOWERS AND THUNDERSTORMS DEVELOPED THIS AFTERNOONMAINLY OVER THE SOUTHWEST SECTION OF PUERTO RICO. THE HEAVIESTRAINFALL WAS OBSERVED OVER PENUELAS...GUAYANILLA AND SABANA GRANDE.ALSO...EARLY THIS AFTERNOON SOME SHOWERS AFFECTED SAINTCROIX...BUT THIS ACTIVITY DISSIPATED RAPIDLY. HIGH PRESSURE ATUPPER LEVEL OF THE ATMOSPHERE IS EXPECTED TO SHIFT WEST...AS ANUPPER LEVEL TROUGH MOVES OVER THE AREA. THIS UPPER LEVELDISTURBANCE...WILL INCREASE THE MOISTURE LOCALLY...WHICH WILL AIDIN THE DEVELOPMENT OF SHOWERS AND THUNDERSTORMS...FIRST...OVER THECOASTAL WATERS BETWEEN THE U.S. VIRGIN ISLANDS AND THE EASTERNSECTION OF PUERTO RICO...AND THEN...WILL PROPAGATE WEST OVER MOSTOF THE AREA. ALTHOUGH SHOWER ACTIVITY IS NOT EXPECTED TO BEWIDESPREAD...SOME SHOWERS AND THUNDERSTORMS ARE EXPECTEDTONIGHT...MAINLY OVER THE U.S. VIRGIN ISLANDS AND EASTERN PUERTORICO.

AS THIS TROUGH CONTINUES MOVING SLOWLY WESTWARD...CONDITIONS ATUPPER LEVEL OF THE ATMOSPHERE WILL BECOME MORE FAVORABLE FORAFTERNOON CONVECTION EACH DAY...MAINLY OVER THE INTERIOR SECTIONSOF PUERTO RICO. THE WETTEST DAY IN THE FORECAST PERIOD WILL BESUNDAY...WHEN A TROPICAL WAVE CURRENTLY NEAR 53 WESTLONGITUDE...WILL APPROACH THE LOCAL AREA. THE COMBINATION OFTHESE TWO FEATURES...PROMISE TO BRING ACTIVE WEATHER OVER THEREGION LATE SATURDAY INTO SUNDAY MORNING. IN THE LONG TERMRANGE...NO SIGNIFICANT WEATHER EVENTS ARE FORECAST TO AFFECT THELOCAL REGION AT THIS TIME.

&&

.AVIATION...MOSTLY VFR CONDS WILL PREVAIL ACROSS ALL TAF SITESTHROUGH THE FORECAST PERIOD. SOME SHRA MAY BRUSH THE NORTH AND EASTCOASTAL SECTIONS OF PR THIS EVENING AND OVERNIGHT...PRODUCING BRIEFPERIODS OF MVFR ACROSS TIST...TISX AND TJSJ. FOR TOMORROWAFTERNOON...CONVECTION ARE EXPECTED TO DEVELOP ACROSS CENTRAL ANDWESTERN PR BTWN 21/17Z AND 21/21Z. AS A RESULT...BRIEF MVFR CONDSPOSSIBLE NEAR TJMZ AND TJBQ...WITH MTN TOP OBSCR OVR INTERIOR PR.WINDS FM SFC TO 30KFT WILL BE MAINLY FM THE E-NE BTW 10-15 KTS.

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR THE FOLLOWING MUNICIPALITIES...

IN PUERTO RICO LAJAS...MARICAO...SABANA GRANDE...SAN GERMAN AND YAUCO

* UNTIL 430 PM AST

* AT 230 PM AST...DOPPLER RADAR INDICATED SHOWERS AND THUNDERSTORMSWITH VERY HEAVY RAIN OVER THESE MUNICIPALITIES MOVING TO THESOUTHWEST AT AROUND 10 MPH. RAINFALL RATES GREATER THAN ONE INCH PERHOUR HAVE BEEN OBSERVED WITH THESE SHOWERS. THIS COULD BE ENOUGH TOCAUSE FLOODING OF POOR DRAINAGE AND LOW LYING AREAS AS WELL AS SHARPRISES IN AREA STREAMS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR THE FOLLOWING MUNICIPALITIES...

IN PUERTO RICO GUAYANILLA...PENUELAS...PONCE...UTUADO...YAUCO AND ADJUNTAS

* UNTIL 400 PM AST

* AT 200 PM AST...DOPPLER RADAR INDICATED SHOWERS AND THUNDERSTORMSWITH VERY HEAVY RAIN OVER THESE MUNICIPALITIES MOVING TO THESOUTHWEST AT AROUND 10 MPH. RAINFALL RATES GREATER THAN ONE INCH PERHOUR HAVE BEEN OBSERVED WITH THESE SHOWERS. THIS COULD BE ENOUGH TOCAUSE FLOODING OF POOR DRAINAGE AND LOW LYING AREAS AS WELL AS SHARPRISES IN AREA STREAMS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

.SYNOPSIS...A MID TO UPPER LEVEL RIDGE WILL GENERALLY REMAIN INCONTROL OF THE LOCAL WEATHER PATTERN THROUGH TONIGHT...BEFORE ANAPPROACHING TUTT AND ITS LOWER LEVEL REFLECTIONS MOVE VERY SLOWLYWEST TOWARD AND THEN ACROSS THE LOCAL REGION FRIDAY THROUGH ATLEAST SUNDAY...WITH THE UPPER LEVEL FEATURE POSSIBLY LINGERINGACROSS THE EASTERN CARIBBEAN THROUGH MONDAY AND TUESDAY.

&&

.DISCUSSION...EXPECT INCREASING MOISTURE TODAY AND LINGERINGMOISTURE TONIGHT THROUGH FRIDAY TO COMBINE WITH LOCAL EFFECTS ANDMARGINALLY FAVORABLE UPPER LEVEL WIND CONDITIONS...TO PRODUCE SOMECLOUDINESS...SCATTERED TO NUMEROUS SHOWERS AND ISOLATEDTHUNDERSTORMS OVER PARTS OF THE LOCAL ISLANDS. IN ADDITION...ADEVELOPING LOW LEVEL SOUTHEAST FLOW TODAY AND CONTINUING FORFRIDAY...SHOULD ONCE AGAIN ALLOW NORTH COASTAL TEMPERATURES TO BEVERY WARM TO HOT...DESPITE SOMEWHAT LIMITED SUNSHINE AT TIMES.SATURDAY SHOULD START OUT FAIRLY DRY...BEFORE MOISTURE INCREASESDURING THE DAY AND LINGERS THROUGH MOIST OF SUNDAY...YIELDINGSIMILAR WEATHER CONDITIONS AS THOSE EXPECTED FOR TODAY ANDFRIDAY. UPPER LEVEL CONDITIONS APPEAR TO REMAIN MARGINAL SATURDAYBUT BECOME MORE FAVORABLE FOR AIDING IN THE DEVELOPMENT OFCONVECTION SUNDAY...SO EXPECT A BIT MORE ACTIVITY THEN. BY SUNDAYNIGHT AND MONDAY AND PROBABLY CONTINUING THROUGH TUESDAY...TUTTFINALLY MOVES TO A MORE FAVORABLE LOCATION TO AID IN CONVECTIONLOCALLY BUT MOISTURE APPEARS TO BE SOMEWHAT LIMITED. THUS...EXPECTEARLY NEXT WEEK TO FEATURE A CONTINUATION OF SOME CLOUDINESS...SHOWERS AND A COUPLE OF THUNDERSTORMS EACH DAY.

&&

.AVIATION...MOSTLY VFR CONDS WILL PREVAIL ACROSS ALL TAF SITESTHROUGH THE FORECAST PERIOD. PASSING SHOWERS WILL AFFECT THE LOCALWATERS EARLY TODAY. SOME SHRA MAY ALSO BRUSH THE NORTH AND EASTCOASTAL SECTIONS OF PR THIS MORNING. AFTERNOON CONVECTION ISEXPECTED TO DEVELOP ACROSS CENTRAL AND SW PR BTWN 20/17Z AND20/21Z. AS A RESULT...BRIEF MVFR CONDS ARE POSSIBLE NEAR TJMZ ANDTJPS...WITH MTN TOP OBSCR OVR INTERIOR PR. WINDS FM SFC TO 25KFTWILL BE MAINLY FM THE E-NE BTWN 10 AND 15 KTS.

&&

.MARINE...GENERALLY EXPECT WINDS OF 16 KNOTS OR LESS AND SEAS OF5 FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH AT LEASTSATURDAY. MARINERS SHOULD REMAIN ON THE LOOKOUT FOR SCATTEREDSHOWERS AND ISOLATED THUNDERSTORMS OVER PARTS OF THE WATERSDURING THE FORECAST PERIOD.

* URBAN AND SMALL STREAM FLOOD ADVISORY FOR THE FOLLOWING MUNICIPALITIES...

IN PUERTO RICO ANASCO...MOCA...RINCON AND AGUADA

* UNTIL 430 PM AST

* AT 235 PM AST...DOPPLER RADAR INDICATED SHOWERS AND THUNDERSTORMSWITH VERY HEAVY RAIN OVER THESE MUNICIPALITIES MOVING TO THE WEST ATAROUND 10 MPH. RAINFALL RATES GREATER THAN ONE INCH PER HOUR HAVEBEEN OBSERVED WITH THESE SHOWERS. THIS COULD BE ENOUGH TO CAUSEFLOODING OF POOR DRAINAGE AND LOW LYING AREAS AS WELL AS SHARP RISESIN AREA STREAMS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

AT 125 PM AST...DOPPLER RADAR INDICATED SHOWERS AND THUNDERSTORMSWITH VERY HEAVY RAIN OVER THESE MUNICIPALITIES MOVING TO THESOUTHWEST AT AROUND 10 MPH. RAINFALL RATES GREATER THAN ONE INCH PERHOUR HAVE BEEN OBSERVED WITH THESE SHOWERS. THIS COULD BE ENOUGH TOCAUSE FLOODING OF POOR DRAINAGE AND LOW LYING AREAS AS WELL AS SHARPRISES IN AREA STREAMS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

* AT 125 PM AST...DOPPLER RADAR INDICATED SHOWERS AND THUNDERSTORMSWITH VERY HEAVY RAIN OVER THESE MUNICIPALITIES MOVING TO THESOUTHWEST AT AROUND 10 MPH. RAINFALL RATES GREATER THAN ONE INCH PERHOUR HAVE BEEN OBSERVED WITH THESE SHOWERS. THIS COULD BE ENOUGH TOCAUSE FLOODING OF POOR DRAINAGE AND LOW LYING AREAS AS WELL AS SHARPRISES IN AREA STREAMS.

MOST FLOOD DEATHS OCCUR IN AUTOMOBILES. NEVER DRIVE YOUR VEHICLE INTOAREAS WHERE THE WATER COVERS THE ROADWAY. FLOOD WATERS ARE USUALLYDEEPER THAN THEY APPEAR. JUST ONE FOOT OF FLOWING WATER IS POWERFULENOUGH TO SWEEP VEHICLES OFF THE ROAD. WHEN ENCOUNTERING FLOODEDROADS MAKE THE SMART CHOICE...TURN AROUND...DONT DROWN.

.SYNOPSIS...UPPER LEVEL RIDGE WILL CONTINUE TO DOMINATE THE LOCALREGION THROUGH AT LEAST SATURDAY. UPPER LEVEL TROUGH WILL MOVETHROUGH THE AREA SATURDAY THROUGH MID NEXT WEEK.

&&

.DISCUSSION...SOME SHOWERS WITH ISOLATED STRONG THUNDERSTORMSDEVELOPED THIS AFTERNOON OVER THE WEST AND SOUTHWESTERN SECTIONSOF PUERTO RICO. REST OF PUERTO RICO REMAINED MOSTLY SUNNY SKIESWITH LITTLE SHOWER ACTIVITY. LATEST SATELITE IMAGES AS WELL ASTPW PRODUCT FROM CIMSS INDICATED A SLOT OF DRIER AIR MOVING INFROM THE NORTHEAST...AND WILL LIMIT THE SHOWER ACTIVITY TONIGHTAND EARLY THURSDAY. ANOTHER AREA OF MOISTURE...WILL MOVE OVER THEAREA THURSDAY...WHICH WILL FAVOR THE DEVELOPMENT OF SHOWERS ANDTHUNDERSTORMS ONCE AGAIN THURSDAY AFTERNOON MAINLY OVER HECORDILLERA CENTRAL OF PUERTO RICO. SJU-GFS 3KM AGL WINDSTREAMLINES SHOW WINDS SHIFTING SOUTHEAST BY FRIDAY. THIS WILLALLOW FOR CONVECTION TO DEVELOP NORTH OF THE CORDILLERACENTRAL...WITH STREAMERS EXPECTED TO DEVELOP FROM EL YUNQUE RAINFOREST AND CONTINUING NORTHWEST TO SAN JUAN METRO AREA. ANOTHERAREA AFFECTED WILL BE THE NORTHWEST SECTION OF PUERTO RICO.

AN UPPER LEVEL TROUGH...IS FORECAST TO PASS OVER PUERTO RICO FROMSATURDAY THROUGH AT LEAST TUESDAY NEXT WEEK...WHICH WILLCONTRIBUTE FOR BETTER CHANCES FOR SHOWERS AS THE TROUGH MOVES IN AMORE FAVORABLE AREA FOR SHOWER AND THUNDERSTORM DEVELOPMENT.ALSO...MOISTURE AT THE SURFACE WILL INCREASE SOME MORE...AS ATROPICAL WAVE/INDUCE SURFACE TROUGH MOVES OVER THE REGION. LATERIN THE FORECAST PERIOD...BETWEEN DAY 5 THROUGH 8...WINDS AREEXPECTED TO SHIFT BACK TO THE NORTHEAST...WHICH WILL COOL DOWN ALITTLE BIT...THE MAXIMUM TEMPERATURES OVER THE AREA.

&&

.AVIATION...BRIEF PERIODS OF MVFR OR EVEN IFR CONDITIONS AREEXPECTED TO CONTINUE ACROSS TJMZ AND TISX UNTIL AT LEAST 19/22Z.AFTER THAT...MOSTLY VFR CONDITIONS WILL PREVAIL ACROSS ALL TAFSITES FOR THE NEXT 12 HRS. HOWEVER...AFT 20/17Z BRIEF MVFRCONDITIONS AND LOCAL MOUNTAIN OBSCURATIONS ARE POSSIBLE ACROSS THECORDILLERA CENTRAL THROUGH ABOUT 20/22Z. ALSO...MVFR CEILINGS AREPOSSIBLE OVER TKPK AND TNCM. EAST WINDS WILL CONTINUE AT AROUND 10TO 15 KTS FROM THE SURFACE TO AROUND 25KFT.

.SYNOPSIS...MID TO UPPER LEVEL RIDGE WILL REMAIN IN CONTROL OF THELOCAL WEATHER PATTERN THROUGH TONIGHT...BEFORE AN APPROACHINGTUTT AND ITS LOWER LEVEL REFLECTIONS MOVE VERY SLOWLY WEST TOWARDAND THEN ACROSS THE LOCAL REGION THURSDAY THROUGH SATURDAY ANDPROBABLY SUNDAY ALSO.

&&

.DISCUSSION...FOR TODAY AND TONIGHT...ALTHOUGH SOMEWHAT DRIER AIRWILL TRY TO WORK INTO THE LOCAL AREA FROM THE EAST NORTHEAST...EXPECT THAT SUFFICIENT MOISTURE LEFT BEHIND TROPICAL WAVE WILLCOMBINE WITH LOCAL EFFECTS AND GENERALLY FAVORABLE UPPER LEVELVENTILATION...TO PRODUCE SOME CLOUDINESS...SCATTERED TO NUMEROUSSHOWERS AND ISOLATED THUNDERSTORMS OVER PARTS OF THE LOCALISLANDS. THEN...FOR THURSDAY AND FRIDAY...MOISTURE APPEARS A BITDEEPER OVERALL BUT FA SHOULD GENERALLY REMAIN ON THE SUBSIDENTSIDE OF AFOREMENTIONED APPROACHING TUTT. SO...AGAIN EXPECT ASIMILAR PATTERN WITH SOME CLOUDINESS...SCATTERED TO NUMEROUSSHOWERS AND ISOLATED THUNDERSTORMS. SATURDAY AND SUNDAY SHOULDOFFER LIMITED OVERALL CHANGE FROM THE PREVIOUS DAYS...AS DYNAMICSIMPROVE DUE TO LOCATION OF TUTT AND ASSOCIATED LOWER LEVELREFLECTIONS. AT THIS POINT...IT APPEARS THAT SATURDAY SHOULD BETHE DRIEST OF THE WEEKEND DAYS DUE TO LIMITED MOISTURE...WITHSUNDAY LOOKING TO BE THE MOST ACTIVE DAY...AS TUTT AXIS AND MOISTSURGE MOVE ACROSS THE FA DURING THE TIME OF MAX HEATING.

&&

.AVIATION...SCT SHRA/TSRA IN THE WAKE OF THE TROPICAL WAVE WILLCONTINUE TO AFFECT THE LOCAL FLYING AREA THROUGH THE FORECASTPERIOD. AS A RESULT...BRIEF PERIODS OF MVFR CONDS ARE POSSIBLEMAINLY ACROSS TIST AND TJSJ IN PASSING SHRA/TSRA THRU AT LEAST19/16Z. AFT 19/16Z...SHRA/TSRA WILL DEVELOP OVER CENTRAL ANDSOUTHWEST PR...CREATING MOUNTAIN OBSCURATIONS AND POSSIBLYPERIODS OF MVFR/IFR CONDS NEAR TJMZ AND TJPS. WINDS WILL CONTINUEMAINLY EAST AT 10 TO 15 KTS.

&&

.MARINE...GENERALLY EXPECT WINDS OF 16 KNOTS OR LESS AND SEAS OF5 FEET OR LESS ACROSS THE REGIONAL WATERS THROUGH AT LEAST FRIDAY.MARINERS SHOULD REMAIN ON THE LOOKOUT FOR CONTINUED SHOWERS ANDTHUNDERSTORMS ACROSS PARTS OF THE REGIONAL WATERS DURING THEFORECAST PERIOD.

.UPDATE...AFTERNOON CONVECTION ACROSS WESTERN PUERTO RICODIMINISHED LATE IN THE AFTERNOON AND ONLY PASSING SHOWERS FROM THEEAST REMAINED OVER THE AREA. SOME OF THESE SHOWERS AFFECTEDWESTERN PUERTO RICO AND THE U.S. VIRGIN ISLANDS. EVEN THOUGHCONDITIONS ARE EXPECTED TO IMPROVE OVERNIGHT...ISOLATED TOSCATTERED PASSING SHOWERS ARE POSSIBLE...AFFECTING THE AREAWATERS...THE U.S. VIRGIN ISLANDS...AND EASTERN PUERTO RICO.

SHORT TERM FORECAST WAS ADJUSTED SINCE LATEST GUIDANCE AND CURRENTOBSERVATIONS SUGGEST THAT MOST OF THE SHOWER AND THUNDERSTORMACTIVITY FOR WEDNESDAY AFTERNOON WILL BE ACROSS SOUTHWESTERNPUERTO RICO. THE PREVIOUS DISCUSSION STILL HOLDS IN TERMS OF THELONG RANGE FORECAST AS THERE HAS BEEN NO SIGNIFICANT CHANGE IN THEGUIDANCE IN THE LARGER SCALE AND IN THE LONG TERM.

.SYNOPSIS...A MID TO UPPER LEVEL RIDGE PATTERN WILL CONTINUE TOPREVAIL ACROSS THE LOCAL AREA THROUGH WEDNESDAY. CUTT OFF LOW ISEXPECTED TO DEVELOP ACROSS THE CENTRAL ATLANTIC WITH A TROUGHEXTENDING ACROSS THE LOCAL AREA THURSDAY THROUGH AT LEAST THEUPCOMING WEEKEND. TROPICAL WAVE WILL CONTINUE TO MOVE ACROSS THECARIBBEAN WATERS THROUGH THE REST OF THE DAY.

&&

.DISCUSSION...UPPER LEVEL RIDGE IS EXPECTED TO HOLD OVER THE NEXT24 HOURS OR SO...WITH UPPER LEVEL ENVIRONMENT REMAINING FAVORABLEFOR DEEP CONVECTION. THIS WILL COMBINE WITH AFOREMENTIONEDTROPICAL WAVE TO PRODUCE PERIODS OF SHOWERS AND THUNDERSTORMSACROSS PORTIONS OF THE LOCAL ISLANDS THIS AFTERNOON THROUGH ATLEAST EARLY WEDNESDAY MORNING.

CUT OFF LOW IS EXPECTED TO DEVELOP ACROSS THE CENTRAL ATLANTIC WITHA TROUGH EXTENDING ACROSS THE LOCAL AREA THURSDAY THROUGH AT LEASTTHE UPCOMING WEEKEND. AS THE TROUGH ENTERS THE EASTERN CARIBBEAN...A RAPID EROSION OF AVAILABLE MOISTURE IS EXPECTED. HOWEVER...LOCALAND DIURNAL EFFECTS WILL COMBINE TO PRODUCE AFTERNOON SHOWERS ANDSTRONG THUNDERSTORMS ACROSS CENTRAL AND WEST PUERTO RICO THURSDAYAND FRIDAY. ENVIRONMENTAL CONDITIONS WILL QUICKLY IMPROVE DURINGTHE WEEKEND AS THE TUTT MOVES FURTHER WEST AND LIKELY FAVOR ANINCREASE IN CONVECTIVE ACTIVITY.

&&

.AVIATION...SEVERAL UNDULATIONS IN THE TROPICAL WAVE ARE BRINGING ASERIES OF SHRA/TSRA BANDS TO THE AREA. ONE IS JUST EAST OF THELEEWARD ISLANDS AND ONE HAS PASSED TISX...THE LATTER IS MOVING AWAYFROM THE AREA. EXPECT BRIEF MVFR AND WIDESPREAD MTN OBSCURATIONS NOWTHROUGH AT LEAST 19/04Z AT MOST TAF SITES...BUT ESPECIALLY ARND TJMZAND TKPK. LLVL WINDS ESE ARND 15 KT UP THROUGH 19 KFT AND CHANGINGLITTLE.

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.MARINE...SEAS 3-5 FT EXPECTED THROUGH MOST OF THE WEEK. SHOWERSAND THUNDERSTORMS ARE LIKELY ACROSS THE REGIONAL WATERS TODAY ASTHE TROPICAL WAVE MOVES THROUGH THE CARIBBEAN WATERS.